Question

In ap a.p. the sum of n terms common difference and last term are 136 ,4 and 31 respectively. Find the value of n.

Answer 1

Here sn=136

An=31

d=4

given

Sn= n/2 (a+an)

136=n/2 (a+31)

Sn=n/2 (2a+(n-1)d)

Apply this formula u vll get the answer

Hope it helps☺