Choose correct alternative that will same pattern and fill in the blank spaces. 7, 6, 10 ,27, 104,

In following number series, two terms have been put within brackets. Choose the appropriate option

Choose correct alternative that will same pattern and fill in the blank spaces. 7, 6, 10 ,27, 104, __

A. 520

B. 420

C. 515

D. 525

Answer: C . 515

Justification:

Here,

7 * 1 - 1 = 6

6 * 2 - 2 = 10

10 * 3 - 3 = 27

27 * 4 - 4 = 104

So 104 * 5 - 5 = 515