## Sequences and Series

#### Sequences and Series

1. 2, 15, 41, 80,132, ?

1. Series pattern
+ 13, + 26, + 39, + 52, + 65

##### Correct Option: A

Series pattern
+ 13, + 26, + 39, + 52, + 65
∴ Missing term = 132 + 65 = 197

Direction: What should come in place of the question mark in each of the following number series ?

1. 12, 15, 36, ?, 480, 2415, 14508

1. Series pattern
12 x 1 + 3 x 1 = 15
15 x 2 + 3 x 2 = 36
36 x 3 + 3 x 3 = 117
Should come in place of ?
117 x 4 + 3 x 4 = 480

##### Correct Option: C

Series pattern
12 x 1 + 3 x 1 = 15
15 x 2 + 3 x 2 = 36
36 x 3 + 3 x 3 = 117
Should come in place of ?
117 x 4 + 3 x 4 = 480
480 x 5 + 3 x 5 = 2415
2415 x 6 + 3 x 6 =14508

1. 1220, 244, ....., 9.76, 1.952, ?

1. Series pattern
Previous number / 5

##### Correct Option: A

Series pattern
Previous number/5
∴ Missing term = 244/5 = 48.8

1. What is the 507th term of the sequence 1, –1, 2, –2, 1, –1, 2, – 2, 1, ....?

1. On the basis of above given series ,
Clearly, repetition takes place for each set of four terms.
Hence, 507th term will be 2507, when divided by 4, gives 3 as remainder and 3rd term is 2.

##### Correct Option: D

On the basis of above given series ,
Clearly, repetition takes place for each set of four terms.
Hence, 507th term will be 2507, when divided by 4, gives 3 as remainder and 3rd term is 2. Thus , option D is correct answer.

1. 1, 9, 25, 49, 81, ?

1. 12, 32, 52, 72, 92, 112

##### Correct Option: A

Series pattern
12, 32, 52, 72, 92, 112
So missing term = 112 = 121