C-13-Q061mediumsingle_mcq

If the sum of the first $n$ terms of a series is $n(n + 1)$ , the sum of the first $10$ terms is —

a $100$
b $110$
c $120$
d $90$

ব্যাখ্যা

Substituting $n=10$ into the given formula gives $S_{10}=10(10+1)=10\times 11=110$ . No term-by-term addition is needed since the partial-sum formula is supplied directly.

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Finite Series — সব প্রশ্ন দেখুন (160টি) →

If the sum of the first nnn terms of a series is n(n+1)n(n + 1)n(n+1), the sum of the first 101010 terms is —

ব্যাখ্যা

এই অধ্যায়ের আরও প্রশ্ন

If the sum of the first nnn terms of a series is n(n+1)n(n + 1)n(n+1), the sum of the first 101010 terms is —

ব্যাখ্যা

এই অধ্যায়ের আরও প্রশ্ন

If the sum of the first $n$ terms of a series is $n(n + 1)$ , the sum of the first $10$ terms is —

If the sum of the first $n$ terms of a series is $n(n + 1)$ , the sum of the first $10$ terms is —