6, 11, 20, 32, 42, 56, 72

Answer: Option [C]

The pattern is 2^{2} + 2, 3^{2} + 3, 4^{2} + 4, 5^{2} + 5, 6^{2} + 6, 7^{2} + 7, 8^{2} + 8

So the wrong number is 32

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Questions

1
In the following number series only one number is wrong. Find out the wrong number.

6, 11, 20, 32, 42, 56, 72

Answer: Option [C]

The pattern is 2^{2} + 2, 3^{2} + 3, 4^{2} + 4, 5^{2} + 5, 6^{2} + 6, 7^{2} + 7, 8^{2} + 8

So the wrong number is 32

2
In the following number series only one number is wrong. Find out the wrong number.

6, 10, 18, 30, 46, 66, 91, 120

Answer: Option [B]

The pattern is + 4, +8, 12, +16, +20, +24, +30

So the wrong number in the series is 91

In each of the following questions a number series is given. Below the number series a number is given. This number is followed by A, B, C, D and E. Using the same pattern as in the original series answer the questions.

3 8 12, 32, 108, 448, 22603 A B C D E

What will be come in place of C ?

Answer: Option [D]

The pattern is x 1 + 4, x 2 + 8, x 3 + 12, x 4 + 16, x 5 + 20

So, 3 x 1 + 4 = 7

So, 7 x 2 + 8 = 22

So, 22 x 3 + 12 = 78

So, 78 x 4 + 16 = 328 which replaces C

4
5, 4, 10, 27, 77, 380

6 A B C D E

What will be come in place of D ?

Answer: Option [B]

The pattern is x 1 - 1, x 2 - 2, x 3 - 3, x 4 - 4, x 5 - 5

So, 6 x 1 - 1 = 5

So, 5 x 2 - 2 = 8

So, 8 x 3 - 3 = 21

So, 21 x 4 - 4 = 80 which replaces D

5
What will come in place of question mark in the following number series ?

1, 3, 7, 15, ?, 63, 127

Answer: Option [D]

The pattern is

2^{1} - 1 = 1

2^{2} - 1 = 3

2^{3} - 1 = 7

2^{4} - 1 = 15

2^{5} - 1 = 31

2^{6} - 1 = 63

2^{7} - 1 = 127

So, 31 will replace the question mark.