Question

How many two digit numbers are divisible by 3? 

(a) 25 (b) 30 (c) 32 (d) 36 

Answer 1

The two-digit numbers divisible by 3 are 12, 15, 18,…… 99. 

Clearly, these number are in AP.

Here, a = 12 and d = 15-12 = 3

Let this AP contains n terms. Then.

Thus, there are 30 two-digit numbers divisible by 3.