Question

which term of the AP 3,15,27,39.....is 771?​

Answer 1

Answer:

a=3, d=15-3=12, an=771, n=?

an=a+(n-1)d

771=3+(n-1)12

771-3=(n-1)12

768 = (n-1)12

768/12 =(n-1)

64 =(n-1)

64+1 = n

65 = n