The sum of first 7 terms of an AP is 10 and that of next 7 terms is 17. Find the AP.
To Find: AP
Given: Sum of first 7 terms = 10
Sum of next 7 terms = 17
According to the problem,
Sum of first 14 terms of the given AP is 10 + 17 = 27.
So we can say
Solving the equations we get 14a + 42d = 20…(i) and
14a + 91d = 27… (
subtracting (i)from (ii)we get 49d = 7
⇒a = 1