Question

2, 7, 9, 3.8, 11,4,9,13, (?), 10, 15. The value of ? is
a) 3
b) 4
c) 5
d) 6​

Answer 1

In the series when we add the first two numbers we get the third number.

2 + 7 = 9

3 + 8 = 11

4 + 9 = 13

(?) + 10 = 15; now, 15 – 10 = 5; since 5 + 10 = 15

Answer: 5