Question

Find sum of 100 term of A.P. -70, -67, -64...​

Answer 1

Step-by-step explanation:

a=72,d=70−72=68−70=66−68=−2

So the given sequence is in AP

Let a

n

=40

General term : a

n

=a+(n−1)d

a+(n−1)d=40

72+(n−1)(−2)=40

72−2n+2=40

2n=34

n=17

Hence, the 17th term of the given sequence is 40.