The missing number in the sequence 5,6,15,…?…. 89,170,291 is:

(1) 50 (2) 40 (3) 42 (4) 32

Solution:

The pattern of the given number series is :

5 + 1² = 6

6 + 3² = 15

15 +5²= 40

40+7²= 89

89+9²= 170

Then the missing number is 40.