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What should come in place of the question mark (?) in the given series?9, 13, 21, 33, 49, ?​​​
Question

What should come in place of the question mark (?) in the given series?
9, 13, 21, 33, 49, ?​​​

A.

71

B.

70

C.

69

D.

68

Correct option is C

Given: 9, 13, 21, 33, 49, ?​​
Logic: Double difference is increasing + 4 place.
13 - 9 = 4
21 - 13 = 8
33 - 21 = 12
49 - 33 = 16
The difference are 4, 8, 12 and 16
So, the next difference is 20.
49 + 20 = 69
So, the missing term is 69.
Thus, correct option is (c).

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