Question

1. Which term of the AP: 121, 117, 113,..., is
its first negative term?
[Hint: Find n for a <0]​

Answer 1

Explanation:

a=121

d=117-121= -4

an=0

an=a+(n-1)d

0=121+(n-1)(-4)

-121=-4n+4

-121-4= -4n

-125= -4n

-125/-4=n

n=31.26

hence first neg term will be 32