अनुक्रम \(2,4,7,11,16,\ldots\) में (20)वाँ पद क्या होगा?
What is the (20)th term of the sequence \(2,4,7,11,16,\ldots\)?
Explanation opens after your attempt
Correct Answer
C. (211)
Concept
It adds consecutive numbers starting from (1), so (a_n=1+\frac{n(n+1)}{2}). Thus \(a_{20}=1+\frac{20\times21}{2}=211\).
Why this answer is correct
The correct answer is C. (211). It adds consecutive numbers starting from (1), so (a_n=1+\frac{n(n+1)}{2}). Thus \(a_{20}=1+\frac{20\times21}{2}=211\).
Exam Tip
यह (1) से शुरू होकर क्रमागत संख्याएँ जोड़ता है और (a_n=1+\frac{n(n+1)}{2}) है। \(a_{20}=1+\frac{20\times21}{2}=211\) है।
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