Explanation:

the first 3 digit number will be 102. And the last will be 996.

This is simple maths and number of terms in this series can be calculated with the use of the Formula.

996 = 102 + (n-1)*6 , where 6 is the common difference.

From here, we can say n = 150. So there are 150 such numbers.

Hence, option 2 is the correct answer.