Practice focused topic-wise MCQs with answers and explanations for quick revision and exam preparation.
Difficulty select karke sirf is topic ke focused MCQs practice karein. Score, timer aur explanations student-friendly flow me milenge.
Showing 211-220 of 600 questions.
What is the sum of the last (5) terms in \(1+2+3+\cdots+45\)?
A. (215)
अंतिम (5) पद (41+42+43+44+45=215) हैं। अंतिम पद पूछे जाएं तो पूरा योग निकालना जरूरी नहीं होता। / The last (5) terms are (41+42+43+44+45=215). If last terms are asked, finding the total sum is not necessary.
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B. (231)
\(S_{21}=S_{20}+21=210+21=231\) है। अगले योग के लिए अगला पद जोड़ दें। / \(S_{21}=S_{20}+21=210+21=231\). For the next sum, add the next term.
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C. (201)
अंतर \(S_{36}-S_{30}=666-465=201\) है। यह (31) से (36) तक के योग के बराबर होता है। / The difference is \(S_{36}-S_{30}=666-465=201\). It equals the sum from (31) to (36).
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For which (n) will \(S_n=780\)?
B. (39)
\(S_{39}=\frac{39\times40}{2}=780\) इसलिए (n=39) है। ऐसे प्रश्नों में (n(n+1)) को \(2S_n\) से मिलाएं। / \(S_{39}=\frac{39\times40}{2}=780\), so (n=39). In such questions, match (n(n+1)) with \(2S_n\).
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A figure has (27) rows of dots, and the (k)th row has (k) dots. How many dots are there in total?
A. (378)
कुल बिंदु \(S_{27}=\frac{27\times28}{2}=378\) होंगे। (k)वीं पंक्ति में (k) बिंदु होना प्राकृतिक संख्याओं का योग दिखाता है। / Total dots are \(S_{27}=\frac{27\times28}{2}=378\). Having (k) dots in the (k)th row shows the sum of natural numbers.
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What is the value of \(S_{16}+16\)?
B. (152)
\(S_{16}=136\) है इसलिए \(S_{16}+16=152\)। गणना में \(S_{16}\) को दोबारा \(S_{17}\) न समझें। / \(S_{16}=136\), so \(S_{16}+16=152\). Do not mistake \(S_{16}+16\) for \(S_{17}\).
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What remains after subtracting (1000) from the sum of the first (50) natural numbers?
D. (275)
\(S_{50}=1275\) और (1275-1000=275) है। पहले योग निकालें फिर दी गई क्रिया करें। / \(S_{50}=1275\), and (1275-1000=275). First find the sum and then perform the given operation.
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If \(S_m=210\) and \(S_n=325\), what is the value of (n-m)?
C. (5)
\(S_{20}=210\) और \(S_{25}=325\) इसलिए (n-m=5)। पहले दोनों सूचकांक पहचानें। / \(S_{20}=210\) and \(S_{25}=325\), so (n-m=5). Identify both indices first.
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What is the sum of \(11+12+13+\cdots+30\)?
D. (410)
योग \(S_{30}-S_{10}=465-55=410\) है। (11) से शुरू होने पर पहले (10) पदों का योग घटाएं। / The sum is \(S_{30}-S_{10}=465-55=410\). When it starts from (11), subtract the sum of the first (10) terms.
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The sum of the first (44) natural numbers is equal to which value?
A. (990)
\(S_{44}=\frac{44\times45}{2}=990\) है। (44) का आधा (22) लेकर \(22\times45\) करें। / \(S_{44}=\frac{44\times45}{2}=990\). Take half of (44) as (22) and calculate \(22\times45\).
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