The number of two digit numbers which are divisible by 3 is

1. 33

2. 31

3. 30

4. 29

Two digit numbers which are divisible by 3 are 12, 15, 18, 21, ….. , 99.

The above series is an A.P. with first term = a = 12 and common difference = d = 15 - 12 = 3.

Let 99 be the nth term, we know that

    a_n = a + (n - 1)d
∴ 99 = 12 + (n - 1) × 3
⇒ 99 = 12 + 3n - 3
⇒ 3n + 9 = 99
⇒ 3n = 90
⇒ n = 30.

Hence, Option 3 is the correct option.