How many numbers of two digit are divisible by 3?

Two digit numbers divisible by 3 are 12, 15, 18,… ,99

Hence, a= 12, ,d=3


an= a + (n -1)d


99= 12(n -1)3


99= 9 = 3n


n=30


Hence, the total numbers of two digit divisible by 3 are 30.


16