If the sum of the first $2 n$ terms of $2,5,8, \ldots \ldots$ is equal to the sum of the first $n$ terms of 57,59 , $61 \ldots \ldots$. , then $\mathrm{n}$ is equal to

Question

If the sum of the first $2 n$ terms of $2,5,8, \ldots \ldots$ is equal to the sum of the first $n$ terms of 57,59 , $61 \ldots \ldots$. , then $\mathrm{n}$ is equal to, 10, 12, 11, 13

MARKS App · Accepted Answer

Given, $\frac{2 n}{2}\{2.2+(2 n-1) 3\}=\frac{n}{2}\{2.57+(n-1) 2\}$ or $2(6 n+1)=112+2 n$ or $10 n=110, ~\therefore n=11$

Search any question & find its solution

Looking for more such questions to practice?