Question

The sum of the 4^th and 8th terms of an AP is 24 and the sum of its 6^th and 10^th terms is 44. Find the sum of its first 10 terms.

Answer 1

Let a be the first and d be the common difference of the AP.

Putting d = 5 in (1), we get

a + 5 x 5 = 12

\(\Rightarrow\) a = 12 - 25 = -13

Hence, the required sum is 95.