2,3,5,10,20,40,? | series Logical reasoning | WBCS

Complete the series by finding the missing number from the given options.

2,3,5,10,20,40,?

(a) 65
(b) 75
(c) 60
(d) 80

Correct Answer: d

Solution: 

2+3=5
2+3+5=10
2+3+5+10=20
2+3+5+10+20=40
2+3+5+10+20+40=80