Question

Which term of the A.P is 21,18,15 ……..is - 81?

A] 35th

B] 30th

C] 32nd

D] 34th​

Answer 1

Answer:

35th

Step-by-step explanation:

The series is 21,18,15,...

a=21,d=−3

a

n

=−81

a

n

=a+(n−1)d

−81=21+(n−1)(−3)

−81−21=−3(n−1)

102=3(n−1)

n−1=34

n=34+1=35