Concept-wise Practice

class11 MCQ Questions for Class 11

class11 se related questions ko ek jagah revise karein. Har question me bilingual content, answer feedback aur explanation available hai.

Practice Questions

1581 questions tagged with class11.

भूगोल में स्थान का अध्ययन मुख्य रूप से किस बात से संबंधित है?

In geography the study of location mainly relates to what?

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Correct Answer

A. किसी वस्तु या घटना की स्थितिPosition of an object or phenomenon

Step 1

Concept

Location is basic to geography because every event happens somewhere. Treat location as a core element in exams.

Step 2

Why this answer is correct

The correct answer is A. किसी वस्तु या घटना की स्थिति / Position of an object or phenomenon. Location is basic to geography because every event happens somewhere. Treat location as a core element in exams.

Step 3

Exam Tip

स्थान भूगोल का आधार है क्योंकि हर घटना किसी जगह पर होती है। परीक्षा में स्थान को भूगोल का मूल तत्व मानें।

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स्थानिक गुणों का सबसे सरल अर्थ क्या है?

What is the simplest meaning of spatial attributes?

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Correct Answer

C. किसी वस्तु या घटना की स्थान से जुड़ी विशेषताएँLocation related features of an object or phenomenon

Step 1

Concept

Spatial attributes tell where something is and how it is spread. In exams location is the main clue.

Step 2

Why this answer is correct

The correct answer is C. किसी वस्तु या घटना की स्थान से जुड़ी विशेषताएँ / Location related features of an object or phenomenon. Spatial attributes tell where something is and how it is spread. In exams location is the main clue.

Step 3

Exam Tip

स्थानिक गुण बताते हैं कि कोई वस्तु कहाँ है और उसका फैलाव कैसा है। परीक्षा में स्थान को मुख्य संकेत मानें।

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भूगोल को समाकलनकारी अनुशासन क्यों कहा जाता है?

Why is geography called an integrating discipline?

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Correct Answer

B. क्योंकि यह प्राकृतिक और मानवीय तत्वों को जोड़कर अध्ययन करता हैBecause it studies natural and human elements together

Step 1

Concept

Geography links nature and human activities on the earth. Remember it as an integrating subject for exams.

Step 2

Why this answer is correct

The correct answer is B. क्योंकि यह प्राकृतिक और मानवीय तत्वों को जोड़कर अध्ययन करता है / Because it studies natural and human elements together. Geography links nature and human activities on the earth. Remember it as an integrating subject for exams.

Step 3

Exam Tip

भूगोल पृथ्वी पर प्रकृति और मानव गतिविधियों के संबंधों को जोड़ता है। परीक्षा में इसे समाकलनकारी विषय के रूप में याद रखें।

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यदि \( \binom{n}{2}=45 \) है, तो \( \binom{n}{4} \) का मान क्या होगा?

If \( \binom{n}{2}=45 \), what is the value of \( \binom{n}{4} \)?

Explanation opens after your attempt
Correct Answer

C. (210)

Step 1

Concept

Since \( \binom{10}{2}=45 \), (n=10), so \( \binom{10}{4}=210 \). First find (n), then evaluate the required combination.

Step 2

Why this answer is correct

The correct answer is C. (210). Since \( \binom{10}{2}=45 \), (n=10), so \( \binom{10}{4}=210 \). First find (n), then evaluate the required combination.

Step 3

Exam Tip

\( \binom{10}{2}=45 \) से (n=10), इसलिए \( \binom{10}{4}=210 \)। पहले (n) निकालें, फिर माँगा गया संयोजन रखें।

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योग \( \sum_{r=0}^{4}\binom{6}{r}\binom{8}{4-r} \) का मान क्या है?

What is the value of \( \sum_{r=0}^{4}\binom{6}{r}\binom{8}{4-r} \)?

Explanation opens after your attempt
Correct Answer

C. (1001)

Step 1

Concept

By Vandermonde's identity, the sum is \( \binom{14}{4}=1001 \). In such sums, view it as total selection after adding upper counts.

Step 2

Why this answer is correct

The correct answer is C. (1001). By Vandermonde's identity, the sum is \( \binom{14}{4}=1001 \). In such sums, view it as total selection after adding upper counts.

Step 3

Exam Tip

वैंडरमोंड सर्वसमिका से योग \( \binom{14}{4}=1001 \) है। ऐसे योग में ऊपर की संख्याएँ जोड़कर कुल चयन देखें।

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( (1+x)5(1+x)7 ) में \(x^8\) का गुणांक कितना है?

What is the coefficient of \(x^8\) in ( (1+x)5(1+x)7 )?

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Correct Answer

D. (495)

Step 1

Concept

The product is ( (1+x)^{12} ), so the coefficient is \( \binom{12}{8}=495 \). In binomial products, combine powers first.

Step 2

Why this answer is correct

The correct answer is D. (495). The product is ( (1+x)^{12} ), so the coefficient is \( \binom{12}{8}=495 \). In binomial products, combine powers first.

Step 3

Exam Tip

गुणनफल ( (1+x)^{12} ) है, इसलिए गुणांक \( \binom{12}{8}=495 \)। द्विपद गुणन में घातें जोड़कर सरल करें।

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शब्द BANANA के अक्षरों से (5) अक्षरों का चयन करना है, समान अक्षरों को अलग नहीं माना जाएगा। कुल अलग चयन कितने हैं?

From the letters of the word BANANA, (5) letters are selected, and identical letters are not distinguished. How many distinct selections are possible?

Explanation opens after your attempt
Correct Answer

B. (3)

Step 1

Concept

The valid selections are \(A^3N^2\), \(BA^2N^2\), and \(BA^3N\), so the total is (3). In small repetition questions, list valid distributions directly.

Step 2

Why this answer is correct

The correct answer is B. (3). The valid selections are \(A^3N^2\), \(BA^2N^2\), and \(BA^3N\), so the total is (3). In small repetition questions, list valid distributions directly.

Step 3

Exam Tip

वैध चयन \(A^3N^2\), \(BA^2N^2\), और \(BA^3N\) हैं, इसलिए कुल (3) हैं। छोटे बहुलता प्रश्नों में वैध वितरण सीधे लिखें।

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शब्द MISSISSIPPI के अक्षरों से (4) अक्षरों का चयन करना है, समान अक्षरों को अलग नहीं माना जाएगा। कुल अलग चयन कितने हैं?

From the letters of the word MISSISSIPPI, (4) letters are selected, and identical letters are not distinguished. How many distinct selections are possible?

Explanation opens after your attempt
Correct Answer

C. (21)

Step 1

Concept

Using the limits \(M\le1\), \(I\le4\), \(S\le4\), and \(P\le2\), the total selections are (21). For repeated letters, count bounded integer solutions.

Step 2

Why this answer is correct

The correct answer is C. (21). Using the limits \(M\le1\), \(I\le4\), \(S\le4\), and \(P\le2\), the total selections are (21). For repeated letters, count bounded integer solutions.

Step 3

Exam Tip

अक्षर-सीमाएँ \(M\le1\), \(I\le4\), \(S\le4\), \(P\le2\) रखकर कुल (21) चयन मिलते हैं। बहुलता वाले अक्षरों में सीमित पूर्णांक हल गिनें।

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एक रेखा पर (7) बिंदु और उसके समांतर दूसरी रेखा पर (5) बिंदु हैं। इनसे ऐसे चतुर्भुज कितने बनेंगे जिनके शीर्ष दिए गए बिंदु हों?

There are (7) points on one line and (5) points on another parallel line. How many quadrilaterals can be formed using these points as vertices?

Explanation opens after your attempt
Correct Answer

C. (210)

Step 1

Concept

A quadrilateral needs (2) points from each line, so \( \binom{7}{2}\binom{5}{2}=210 \). Taking (3) points from one line cannot form a quadrilateral.

Step 2

Why this answer is correct

The correct answer is C. (210). A quadrilateral needs (2) points from each line, so \( \binom{7}{2}\binom{5}{2}=210 \). Taking (3) points from one line cannot form a quadrilateral.

Step 3

Exam Tip

चतुर्भुज के लिए हर रेखा से (2) बिंदु चाहिए, इसलिए \( \binom{7}{2}\binom{5}{2}=210 \)। एक ही रेखा से (3) बिंदु लेने पर चतुर्भुज नहीं बनेगा।

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(10) व्यक्तियों में (A) और (B) विशेष हैं। (5) व्यक्ति ऐसे चुनने हैं कि (A) और (B) में से ठीक एक चुना जाए। कुल चयन कितने हैं?

Among (10) persons, (A) and (B) are special. How many ways can (5) persons be chosen so that exactly one of (A) and (B) is selected?

Explanation opens after your attempt
Correct Answer

A. (140)

Step 1

Concept

There are (2) ways to choose the special person and then (4) from the other (8), so \(2\binom{8}{4}=140\). Exactly one means two symmetric cases.

Step 2

Why this answer is correct

The correct answer is A. (140). There are (2) ways to choose the special person and then (4) from the other (8), so \(2\binom{8}{4}=140\). Exactly one means two symmetric cases.

Step 3

Exam Tip

विशेष व्यक्ति चुनने के (2) तरीके और बाकी (4) व्यक्ति (8) में से, इसलिए \(2\binom{8}{4}=140\)। ठीक एक का अर्थ है दो समान मामले।

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(13) व्यक्तियों में दो विशेष व्यक्ति (P) और (Q) हैं। (6) व्यक्ति ऐसे चुनने हैं कि (P,Q) या तो दोनों चुने जाएँ या दोनों न चुने जाएँ। कुल चयन कितने हैं?

Among (13) persons, two particular persons are (P) and (Q). How many ways can (6) persons be chosen so that (P,Q) are either both selected or both not selected?

Explanation opens after your attempt
Correct Answer

C. (792)

Step 1

Concept

If both are selected, count \( \binom{11}{4} \); if neither is selected, count \( \binom{11}{6} \), giving (792). Split either both or neither into two cases.

Step 2

Why this answer is correct

The correct answer is C. (792). If both are selected, count \( \binom{11}{4} \); if neither is selected, count \( \binom{11}{6} \), giving (792). Split either both or neither into two cases.

Step 3

Exam Tip

दोनों चुने जाने पर \( \binom{11}{4} \) और दोनों न चुने जाने पर \( \binom{11}{6} \), कुल (792) है। या तो दोनों या कोई नहीं को दो अलग मामलों में बाँटें।

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(10) व्यक्तियों में से पहले (3) सदस्य वाली समिति और फिर बचे लोगों में से (4) सदस्य वाली अलग नामित समिति बनानी है। कुल तरीके कितने हैं?

From (10) persons, first a named committee of (3) members and then a different named committee of (4) members from the remaining persons are formed. How many ways are possible?

Explanation opens after your attempt
Correct Answer

C. (4200)

Step 1

Concept

The first committee can be formed in \( \binom{10}{3} \) ways and the second in \( \binom{7}{4} \) ways, giving (4200). For named committees, the stages matter.

Step 2

Why this answer is correct

The correct answer is C. (4200). The first committee can be formed in \( \binom{10}{3} \) ways and the second in \( \binom{7}{4} \) ways, giving (4200). For named committees, the stages matter.

Step 3

Exam Tip

पहली समिति \( \binom{10}{3} \) और दूसरी \( \binom{7}{4} \) तरीकों से बनेगी, कुल (4200) है। नामित समितियों में चरणों का क्रम महत्त्व रखता है।

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(1) से (12) तक की संख्याओं में से (4) संख्याएँ ऐसी चुननी हैं जिनका योग सम हो। कुल चयन कितने हैं?

From the numbers (1) to (12), (4) numbers are chosen so that their sum is even. How many selections are possible?

Explanation opens after your attempt
Correct Answer

C. (255)

Step 1

Concept

For an even sum, the number of odd selected numbers can be (0,2,4), giving (255). Focus on how many odd elements are selected, not only on total selection size.

Step 2

Why this answer is correct

The correct answer is C. (255). For an even sum, the number of odd selected numbers can be (0,2,4), giving (255). Focus on how many odd elements are selected, not only on total selection size.

Step 3

Exam Tip

सम योग के लिए विषम संख्याओं की संख्या (0,2,4) हो सकती है, कुल (255) है। चयन की संख्या पर नहीं, विषम चुने गए तत्वों की संख्या पर ध्यान दें।

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(1) से (20) तक की संख्याओं में से (3) संख्याएँ ऐसी चुननी हैं जिनका योग विषम हो। कुल चयन कितने हैं?

From the numbers (1) to (20), (3) numbers are chosen so that their sum is odd. How many selections are possible?

Explanation opens after your attempt
Correct Answer

B. (570)

Step 1

Concept

For an odd sum, choose (1) odd and (2) even or (3) odd numbers, giving (570). Making a parity case table reduces errors.

Step 2

Why this answer is correct

The correct answer is B. (570). For an odd sum, choose (1) odd and (2) even or (3) odd numbers, giving (570). Making a parity case table reduces errors.

Step 3

Exam Tip

योग विषम के लिए (1) विषम और (2) सम या (3) विषम चुनें, कुल (570) है। सम-विषम संयोजन तालिका बनाकर गलती घटती है।

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(1) से (15) तक की संख्याओं में से (4) संख्याएँ चुननी हैं ताकि उनका गुणनफल विषम हो। कुल चयन कितने हैं?

From the numbers (1) to (15), (4) numbers are chosen so that their product is odd. How many selections are possible?

Explanation opens after your attempt
Correct Answer

C. (70)

Step 1

Concept

The product is odd only when all four numbers are odd, so \( \binom{8}{4}=70 \). For product parity, check every factor.

Step 2

Why this answer is correct

The correct answer is C. (70). The product is odd only when all four numbers are odd, so \( \binom{8}{4}=70 \). For product parity, check every factor.

Step 3

Exam Tip

गुणनफल विषम तभी होगा जब चारों संख्याएँ विषम हों, इसलिए \( \binom{8}{4}=70 \)। गुणनफल की सम-विषम प्रकृति में सभी कारकों पर ध्यान दें।

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(12) अवयवों वाले समुच्चय में (4) विशेष अवयव हैं। (5) अवयवों के ऐसे उपसमुच्चय कितने हैं जिनमें कम से कम (2) विशेष अवयव हों?

A set of (12) elements has (4) special elements. How many (5)-element subsets contain at least (2) special elements?

Explanation opens after your attempt
Correct Answer

C. (456)

Step 1

Concept

Taking the number of special elements as (2,3,4) gives (456). With a small special group, directly add valid cases.

Step 2

Why this answer is correct

The correct answer is C. (456). Taking the number of special elements as (2,3,4) gives (456). With a small special group, directly add valid cases.

Step 3

Exam Tip

विशेष अवयवों की संख्या (2,3,4) लेकर योग (456) है। छोटे विशेष समूह में सीधे वैध मामलों को जोड़ना आसान है।

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(10) अवयवों वाले समुच्चय में (a) और (b) विशेष हैं। ऐसे उपसमुच्चय कितने हैं जो (a) को रखते हैं लेकिन (b) को नहीं रखते?

In a set of (10) elements, (a) and (b) are special. How many subsets contain (a) but do not contain (b)?

Explanation opens after your attempt
Correct Answer

B. (256)

Step 1

Concept

(a) is fixed as selected and (b) is fixed as not selected, so the remaining (8) elements are free, giving \(2^8=256\). Fix compulsory states first.

Step 2

Why this answer is correct

The correct answer is B. (256). (a) is fixed as selected and (b) is fixed as not selected, so the remaining (8) elements are free, giving \(2^8=256\). Fix compulsory states first.

Step 3

Exam Tip

(a) निश्चित रूप से चुना और (b) निश्चित रूप से छोड़ा गया, बाकी (8) अवयव स्वतंत्र हैं, इसलिए \(2^8=256\)। निश्चित अवस्थाओं को पहले स्थिर करें।

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(9) अवयवों वाले समुच्चय में (3) विशेष अवयव हैं। (5) अवयवों के कितने उपसमुच्चय ठीक (2) विशेष अवयव रखते हैं?

A set of (9) elements has (3) special elements. How many (5)-element subsets contain exactly (2) special elements?

Explanation opens after your attempt
Correct Answer

C. (60)

Step 1

Concept

The selection is \( \binom{3}{2}\binom{6}{3}=60 \). With exactly (2) special elements, take the remaining (3) from ordinary elements.

Step 2

Why this answer is correct

The correct answer is C. (60). The selection is \( \binom{3}{2}\binom{6}{3}=60 \). With exactly (2) special elements, take the remaining (3) from ordinary elements.

Step 3

Exam Tip

चयन \( \binom{3}{2}\binom{6}{3}=60 \) है। ठीक (2) विशेष होने पर बाकी (3) सामान्य अवयवों से लें।

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(9) अवयवों वाले समुच्चय में (3) विशेष अवयव हैं। (5) अवयवों के ऐसे उपसमुच्चय कितने हैं जिनमें तीनों विशेष अवयव एक साथ न हों?

A set of (9) elements has (3) special elements. How many (5)-element subsets do not contain all three special elements together?

Explanation opens after your attempt
Correct Answer

A. (111)

Step 1

Concept

Subtract \( \binom{6}{2} \) subsets containing all three special elements from total \( \binom{9}{5} \), giving (111). In not-type questions, subtract forbidden selections.

Step 2

Why this answer is correct

The correct answer is A. (111). Subtract \( \binom{6}{2} \) subsets containing all three special elements from total \( \binom{9}{5} \), giving (111). In not-type questions, subtract forbidden selections.

Step 3

Exam Tip

कुल \( \binom{9}{5} \) से तीनों विशेष अवयवों वाले \( \binom{6}{2} \) घटाएँ, उत्तर (111) है। नहीं वाले प्रश्न में निषिद्ध चयन घटाएँ।

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समीकरण \(x_1+x_2+x_3+x_4=18\) के ऐसे शून्य सहित पूर्णांक हल कितने हैं जिनमें \(x_1\le5\) हो?

How many nonnegative integer solutions of \(x_1+x_2+x_3+x_4=18\) satisfy \(x_1\le5\)?

Explanation opens after your attempt
Correct Answer

C. (875)

Step 1

Concept

Subtract \( \binom{15}{3} \) cases with \(x_1\ge6\) from total \( \binom{21}{3} \), giving (875). For upper limits, subtract forbidden solutions.

Step 2

Why this answer is correct

The correct answer is C. (875). Subtract \( \binom{15}{3} \) cases with \(x_1\ge6\) from total \( \binom{21}{3} \), giving (875). For upper limits, subtract forbidden solutions.

Step 3

Exam Tip

कुल \( \binom{21}{3} \) से \(x_1\ge6\) वाले \( \binom{15}{3} \) घटते हैं, उत्तर (875) है। ऊपरी सीमा में प्रतिबंधित हल घटाना आसान है।

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समीकरण \(x_1+x_2+x_3+x_4=20\) में \(x_1\ge5\) और \(x_2,x_3,x_4\ge1\) हों, तो धनात्मक पूर्णांक हलों की संख्या कितनी है?

For \(x_1+x_2+x_3+x_4=20\), with \(x_1\ge5\) and \(x_2,x_3,x_4\ge1\), how many positive integer solutions are there?

Explanation opens after your attempt
Correct Answer

D. (455)

Step 1

Concept

After subtracting minimums (5,1,1,1), (12) remains, so \( \binom{15}{3}=455 \). Subtract unequal minimum conditions first.

Step 2

Why this answer is correct

The correct answer is D. (455). After subtracting minimums (5,1,1,1), (12) remains, so \( \binom{15}{3}=455 \). Subtract unequal minimum conditions first.

Step 3

Exam Tip

न्यूनतम (5,1,1,1) घटाने पर (12) बचता है, इसलिए \( \binom{15}{3}=455 \)। असमान न्यूनतम शर्तों को पहले घटाएँ।

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(12) समान कलमों को (3) विद्यार्थियों में बाँटना है ताकि हर विद्यार्थी को कम से कम (2) कलमें मिलें। कुल वितरण कितने हैं?

How many ways can (12) identical pens be distributed among (3) students so that each gets at least (2) pens?

Explanation opens after your attempt
Correct Answer

C. (28)

Step 1

Concept

After giving (2) pens to each student, (6) pens remain, so \( \binom{8}{2}=28 \). Subtract the minimum condition and then count nonnegative solutions.

Step 2

Why this answer is correct

The correct answer is C. (28). After giving (2) pens to each student, (6) pens remain, so \( \binom{8}{2}=28 \). Subtract the minimum condition and then count nonnegative solutions.

Step 3

Exam Tip

हर विद्यार्थी को (2) देने के बाद (6) कलमें बचती हैं, इसलिए \( \binom{8}{2}=28 \)। न्यूनतम शर्त घटाकर फिर शून्य सहित हल गिनें।

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(4) प्रकार के फलों से (6) फल चुनने हैं और हर प्रकार की मात्रा असीमित है। कुल चयन कितने हैं?

From (4) types of fruits, (6) fruits are to be selected, with unlimited quantity of each type. How many selections are possible?

Explanation opens after your attempt
Correct Answer

B. (84)

Step 1

Concept

This is the number of nonnegative solutions of \(x_1+x_2+x_3+x_4=6\), so \( \binom{9}{3}=84 \). For unlimited identical types, use stars and bars.

Step 2

Why this answer is correct

The correct answer is B. (84). This is the number of nonnegative solutions of \(x_1+x_2+x_3+x_4=6\), so \( \binom{9}{3}=84 \). For unlimited identical types, use stars and bars.

Step 3

Exam Tip

यह \(x_1+x_2+x_3+x_4=6\) के अशून्येतर नहीं बल्कि शून्य सहित हल हैं, इसलिए \( \binom{9}{3}=84 \)। असीमित समान प्रकारों में सितारे और पट्टियाँ लगाएँ।

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(10) व्यक्तियों में (3) विशेष व्यक्ति हैं। (6) सदस्यों की समिति में कम से कम (2) विशेष व्यक्ति होने चाहिए। कुल चयन कितने हैं?

Among (10) persons, (3) are special. A committee of (6) must contain at least (2) special persons. How many selections are possible?

Explanation opens after your attempt
Correct Answer

A. (140)

Step 1

Concept

The cases of exactly (2) special and exactly (3) special persons add to (140). For at least (2), add both valid cases.

Step 2

Why this answer is correct

The correct answer is A. (140). The cases of exactly (2) special and exactly (3) special persons add to (140). For at least (2), add both valid cases.

Step 3

Exam Tip

ठीक (2) विशेष और ठीक (3) विशेष के मामलों का योग (140) है। कम से कम (2) में दोनों वैध मामले जोड़ें।

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(6) दंपतियों में से (5) व्यक्ति चुनने हैं जिनमें ठीक एक विवाहित जोड़ा शामिल हो। कुल चयन कितने हैं?

From (6) couples, (5) persons are chosen with exactly one married couple included. How many selections are possible?

Explanation opens after your attempt
Correct Answer

C. (480)

Step 1

Concept

Choose the couple \( \binom{6}{1} \), then (3) other couples \( \binom{5}{3} \), and one person from each \(2^3\), giving (480). After fixing exactly one couple, choose only one person from each remaining couple.

Step 2

Why this answer is correct

The correct answer is C. (480). Choose the couple \( \binom{6}{1} \), then (3) other couples \( \binom{5}{3} \), and one person from each \(2^3\), giving (480). After fixing exactly one couple, choose only one person from each remaining couple.

Step 3

Exam Tip

जोड़ा \( \binom{6}{1} \), बाकी (3) दंपति \( \binom{5}{3} \), और उनसे एक-एक व्यक्ति \(2^3\), कुल (480) है। ठीक एक जोड़ा रखने के बाद बाकी जोड़ों से केवल एक व्यक्ति चुनें।

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(8) दंपतियों में से (4) व्यक्ति चुनने हैं, पर कोई विवाहित जोड़ा साथ नहीं चुना जाना चाहिए। कुल चयन कितने हैं?

From (8) couples, (4) persons are chosen, but no married couple should be selected together. How many selections are possible?

Explanation opens after your attempt
Correct Answer

D. (1120)

Step 1

Concept

First choose (4) couples and then (1) person from each, giving \( \binom{8}{4}2^4=1120 \). Choosing only one from a couple gives (2) choices.

Step 2

Why this answer is correct

The correct answer is D. (1120). First choose (4) couples and then (1) person from each, giving \( \binom{8}{4}2^4=1120 \). Choosing only one from a couple gives (2) choices.

Step 3

Exam Tip

पहले (4) दंपति चुनें और हर दंपति से (1) व्यक्ति लें, \( \binom{8}{4}2^4=1120 \)। जोड़े से केवल एक चुनने पर (2) विकल्प बनते हैं।

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यदि \( \binom{11}{r}=\binom{11}{r-3} \), तो ( r ) का मान क्या है?

If \( \binom{11}{r}=\binom{11}{r-3} \), what is the value of ( r )?

Explanation opens after your attempt
Correct Answer

B. (7)

Step 1

Concept

By symmetry, (r+(r-3)=11), so (r=7). In \( \binom{n}{a}=\binom{n}{b} \), often (a+b=n) is useful.

Step 2

Why this answer is correct

The correct answer is B. (7). By symmetry, (r+(r-3)=11), so (r=7). In \( \binom{n}{a}=\binom{n}{b} \), often (a+b=n) is useful.

Step 3

Exam Tip

सममिति से (r+(r-3)=11), इसलिए (r=7) है। \( \binom{n}{a}=\binom{n}{b} \) में अक्सर (a+b=n) काम आता है।

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यदि \( \binom{12}{r}=\binom{12}{r+2} \), तो ( r ) का मान क्या है?

If \( \binom{12}{r}=\binom{12}{r+2} \), what is the value of ( r )?

Explanation opens after your attempt
Correct Answer

A. (5)

Step 1

Concept

By symmetry, (r+(r+2)=12), so (r=5). In such questions, make the lower indices add to (n).

Step 2

Why this answer is correct

The correct answer is A. (5). By symmetry, (r+(r+2)=12), so (r=5). In such questions, make the lower indices add to (n).

Step 3

Exam Tip

सममिति से (r+(r+2)=12), इसलिए (r=5) है। ऐसे प्रश्नों में निचले सूचकांकों का योग (n) के बराबर रखें।

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(14) वस्तुओं में से (7) चुननी हैं, जिनमें एक निश्चित (5) वस्तुओं के समूह से ठीक (3) वस्तुएँ हों। कुल चयन कितने हैं?

From (14) objects, (7) are chosen with exactly (3) objects from a fixed group of (5). How many selections are possible?

Explanation opens after your attempt
Correct Answer

A. (1260)

Step 1

Concept

The selection is \( \binom{5}{3}\binom{9}{4}=1260 \). Exactly (3) means the remaining (4) come from outside the fixed group.

Step 2

Why this answer is correct

The correct answer is A. (1260). The selection is \( \binom{5}{3}\binom{9}{4}=1260 \). Exactly (3) means the remaining (4) come from outside the fixed group.

Step 3

Exam Tip

चयन \( \binom{5}{3}\binom{9}{4}=1260 \) है। ठीक (3) का अर्थ है बाकी (4) बाहर वाले समूह से आएँगे।

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ताश की गड्डी से (5) पत्तों का ऐसा हाथ चुनना है जिसमें सभी पत्ते एक ही सूट के हों। कुल कितने हाथ होंगे?

A (5)-card hand is chosen from a deck so that all cards are from the same suit. How many hands are possible?

Explanation opens after your attempt
Correct Answer

D. (5148)

Step 1

Concept

From one suit there are \( \binom{13}{5} \) selections and there are (4) suits, so the count is (5148). Choose the suit and then the cards.

Step 2

Why this answer is correct

The correct answer is D. (5148). From one suit there are \( \binom{13}{5} \) selections and there are (4) suits, so the count is (5148). Choose the suit and then the cards.

Step 3

Exam Tip

किसी एक सूट से \( \binom{13}{5} \) चयन और (4) सूट हैं, इसलिए (5148) है। सूट चुनना और फिर पत्ते चुनना दो चरण हैं।

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