1.  2, 6, 12, 20, 30, 42, 56, (....)
A. 61
B. 64
C. 72
D. 70

Answer: Option C

Explanation:

The pattern is 1 x 2, 2 x 3, 3 x 4, 4 x 5, 5 x 6, 6 x 7, 7 x 8.

So, the next number is 8 x 9 = 72.