Total ways are \(\binom{13}{5}=1287\). Removing all-white \(\binom{6}{5}=6\) and all-black \(\binom{7}{5}=21\) gives (1260).
Step 2
Why this answer is correct
The correct answer is B. (1260). Total ways are \(\binom{13}{5}=1287\). Removing all-white \(\binom{6}{5}=6\) and all-black \(\binom{7}{5}=21\) gives (1260).
Step 3
Exam Tip
कुल \(\binom{13}{5}=1287\) हैं। सभी सफेद \(\binom{6}{5}=6\) और सभी काली \(\binom{7}{5}=21\) हटाने पर (1260) मिलते हैं।
Total ways are \(\binom{16}{5}=4368\). Removing the cases of (0) teacher and (1) teacher gives \(4368-\binom{9}{5}-\binom{7}{1}\binom{9}{4}=3213\).
Step 2
Why this answer is correct
The correct answer is B. (3213). Total ways are \(\binom{16}{5}=4368\). Removing the cases of (0) teacher and (1) teacher gives \(4368-\binom{9}{5}-\binom{7}{1}\binom{9}{4}=3213\).
Step 3
Exam Tip
कुल \(\binom{16}{5}=4368\) हैं। (0) शिक्षक और (1) शिक्षक के मामले हटाने पर \(4368-\binom{9}{5}-\binom{7}{1}\binom{9}{4}=3213\) है।
The element (1) is already chosen so the remaining (3) elements are chosen from (8). The number of ways is \(\binom{8}{3}=56\).
Step 2
Why this answer is correct
The correct answer is B. (56). The element (1) is already chosen so the remaining (3) elements are chosen from (8). The number of ways is \(\binom{8}{3}=56\).
Step 3
Exam Tip
(1) पहले से चुना है इसलिए बाकी (3) तत्व (8) में से चुने जाएंगे। तरीकों की संख्या \(\binom{8}{3}=56\) है।
By Pascal's identity \(\binom{n}{r}+\binom{n}{r+1}=\binom{n+1}{r+1}\). Hence the answer is \(\binom{10}{5}\).
Step 2
Why this answer is correct
The correct answer is A. \(\binom{10}{5}\). By Pascal's identity \(\binom{n}{r}+\binom{n}{r+1}=\binom{n+1}{r+1}\). Hence the answer is \(\binom{10}{5}\).
Step 3
Exam Tip
पास्कल पहचान से \(\binom{n}{r}+\binom{n}{r+1}=\binom{n+1}{r+1}\) होता है। इसलिए उत्तर \(\binom{10}{5}\) है।
Total ways are \(\binom{13}{5}=1287\). Removing only pens \(\binom{7}{5}=21\) and only pencils \(\binom{6}{5}=6\) gives (1260).
Step 2
Why this answer is correct
The correct answer is B. (1260). Total ways are \(\binom{13}{5}=1287\). Removing only pens \(\binom{7}{5}=21\) and only pencils \(\binom{6}{5}=6\) gives (1260).
Step 3
Exam Tip
कुल \(\binom{13}{5}=1287\) हैं। केवल पेन \(\binom{7}{5}=21\) और केवल पेंसिल \(\binom{6}{5}=6\) हटाने पर (1260) है।
Total ways are \(\binom{13}{6}=1716\) and ways with no special student are \(\binom{8}{6}=28\). Hence (1716-28=1688) ways.
Step 2
Why this answer is correct
The correct answer is D. (3003). Total ways are \(\binom{13}{6}=1716\) and ways with no special student are \(\binom{8}{6}=28\). Hence (1716-28=1688) ways.
Step 3
Exam Tip
कुल \(\binom{13}{6}=1716\) हैं और कोई विशेष न हो तो \(\binom{8}{6}=28\) हैं। इसलिए (1716-28=1688) तरीके हैं।
The cases are (3), (4), and (5) doctors. The total is \(\binom{7}{3}\binom{5}{2}+\binom{7}{4}\binom{5}{1}+\binom{7}{5}=546\).
Step 2
Why this answer is correct
The correct answer is C. (581). The cases are (3), (4), and (5) doctors. The total is \(\binom{7}{3}\binom{5}{2}+\binom{7}{4}\binom{5}{1}+\binom{7}{5}=546\).
Step 3
Exam Tip
मामले (3), (4) और (5) डॉक्टरों के हैं। कुल \(\binom{7}{3}\binom{5}{2}+\binom{7}{4}\binom{5}{1}+\binom{7}{5}=546\) है।
Total ways are \(\binom{14}{4}=1001\). Removing only English \(\binom{6}{4}=15\) and only Hindi \(\binom{8}{4}=70\) gives (916) ways.
Step 2
Why this answer is correct
The correct answer is A. (920). Total ways are \(\binom{14}{4}=1001\). Removing only English \(\binom{6}{4}=15\) and only Hindi \(\binom{8}{4}=70\) gives (916) ways.
Step 3
Exam Tip
कुल \(\binom{14}{4}=1001\) हैं। केवल अंग्रेजी \(\binom{6}{4}=15\) और केवल हिंदी \(\binom{8}{4}=70\) हटाने पर (916) तरीके मिलते हैं।
The cases are (2), (3), and (4) chemistry books. The correct sum is \(\binom{8}{2}\binom{5}{2}+\binom{8}{3}\binom{5}{1}+\binom{8}{4}=630\).
Step 2
Why this answer is correct
The correct answer is C. (560). The cases are (2), (3), and (4) chemistry books. The correct sum is \(\binom{8}{2}\binom{5}{2}+\binom{8}{3}\binom{5}{1}+\binom{8}{4}=630\).
Step 3
Exam Tip
मामले (2), (3) और (4) रसायन पुस्तकों के हैं। कुल \(\binom{8}{2}\binom{5}{2}+\binom{8}{3}\binom{5}{1}+\binom{8}{4}=630\) नहीं बल्कि सही जोड़ (280+280+70=630) है।
Total triples are \(\binom{13}{3}=286\) and \(\binom{5}{3}=10\) collinear triples do not form triangles. Hence (286-10=276).
Step 2
Why this answer is correct
The correct answer is C. (276). Total triples are \(\binom{13}{3}=286\) and \(\binom{5}{3}=10\) collinear triples do not form triangles. Hence (286-10=276).
Step 3
Exam Tip
कुल \(\binom{13}{3}=286\) त्रिक हैं और \(\binom{5}{3}=10\) समरेखीय त्रिक त्रिभुज नहीं बनाते। इसलिए (286-10=276) है।
Total pairs are \(\binom{16}{2}=120\) and (6) collinear points give (1) line instead of \(\binom{6}{2}\). Hence (120-15+1=106).
Step 2
Why this answer is correct
The correct answer is B. (106). Total pairs are \(\binom{16}{2}=120\) and (6) collinear points give (1) line instead of \(\binom{6}{2}\). Hence (120-15+1=106).
Step 3
Exam Tip
कुल \(\binom{16}{2}=120\) जोड़ियां हैं और (6) समरेखीय बिंदु \(\binom{6}{2}\) के स्थान पर (1) रेखा देते हैं। इसलिए (120-15+1=106) है।
The cases are choosing (2) or (3) from the first (3). The total is \(\binom{3}{2}\binom{7}{4}+\binom{3}{3}\binom{7}{3}=147\).
Step 2
Why this answer is correct
The correct answer is D. (147). The cases are choosing (2) or (3) from the first (3). The total is \(\binom{3}{2}\binom{7}{4}+\binom{3}{3}\binom{7}{3}=147\).
Step 3
Exam Tip
मामले पहले (3) में से (2) या (3) चुनने के हैं। कुल \(\binom{3}{2}\binom{7}{4}+\binom{3}{3}\binom{7}{3}=147\) है।
The cases are (2), (3), and (4) women. The correct sum is \(\binom{6}{2}\binom{8}{2}+\binom{6}{3}\binom{8}{1}+\binom{6}{4}=595\).
Step 2
Why this answer is correct
The correct answer is B. (665). The cases are (2), (3), and (4) women. The correct sum is \(\binom{6}{2}\binom{8}{2}+\binom{6}{3}\binom{8}{1}+\binom{6}{4}=595\).
Step 3
Exam Tip
मामले (2), (3) और (4) महिलाओं के हैं। कुल \(\binom{6}{2}\binom{8}{2}+\binom{6}{3}\binom{8}{1}+\binom{6}{4}=595\) नहीं बल्कि सही जोड़ (420+160+15=595) है।
