2nd term = (1st term x 2 - 2) = (5 x 2 - 2) = 8 3rd term = (2nd term x 3 - 2) = (8 x 3 - 2) = 22 4th term = (3rd term x 2 - 2) = (22 x 2 - 2) = 42 5th term = (4th term x 3 - 2) = (42 x 3 - 2) = 124 and so on 20 is wrong

Q16. 1, 2, 8, 33, 148, 760, 4626

A. 760

B. 148

C. 2

D. 33

Answer- Option A

Explanation-

2nd term = (1st term x 1 + 1^{2}) = (1 x 1 + 1^{2}) = 2 3rd term = (2nd term x 2 + 2^{2}) = (2 x 2 + 2^{2}) = 8 4th term = (3rd term x 3 + 3^{2}) = (8 x 3 + 3^{2}) = 33 5th term = (4th term x 4 + 4^{2}) = (33 x 4 + 4^{2}) = 148 6th term = (5th term x 5 + 5^{2}) = (148 x 5 + 5^{2}) = 765 760 is wrong

Q17. 1050, 510, 242, 106, 46, 16, 3

A. 46

B. 16

C. 106

D. 510

Answer- Option C

Explanation-

2nd term = (1st term - 30) ÷ 2 =

1050 - 30

2

= 510

3nd term = (2nd term - 26) ÷ 2 =

510 - 26

2

= 242

4nd term = (3rd term - 22) ÷ 2 =

242 - 22

2

= 110.

106 is wrong.

Q18. 32, 36, 41, 61, 86, 122, 171, 235

A. 171

B. 122

C. 86

D. 41

Answer- Option D

Explanation-

2nd term = (1st term) + 2^{2} = 32 + 4 = 36 3rd term = (2st term) + 3^{2} = 36 + 9 = 45 4th term = (3st term) + 4^{2} = 45 + 16 = 61 5th term = (4st term) + 5^{2} = 61 + 25 = 86 3rd term should be 45 instead of 41.

Q19. 3, 8, 18, 46, 100, 210, 432

A. 46

B. 18

C. 100

D. 8

Answer- Option B

Explanation-

2nd term = (1st term x 2 + 2) = 3 x 2 + 2 = 8 3rd term = (2nd term x 2 + 4) = 8 x 2 + 4 = 20 4th term = (3rd term x 2 + 6) = 20 x 2 + 6 = 46 5th term = (4th term x 2 + 8) = 46 x 2 + 8 = 100 and so on 18 is wrong

Q20. 2, 3, 6, 15, 52.5, 157.5, 630

A. 157.5

B. 3

C. 52.5

D. 15

Answer- Option C

Explanation-

2nd term = (1st term x 1.5) = 2 x 1.5 = 3 3rd term = (2nd term x 2) = 3 x 2 = 6 4th term = (3rd term x 2.5) = 6 x 2.5 = 15 5th term = (4th term x 3) = 15 x 3 = 45 52.5 is wrong

Q21. 4, 5, 15, 49, 201, 1011, 6073

A. 15

B. 49

C. 1011

D. 5

Answer- Option D

Explanation-

2nd term = (1st term x 1 + 2) = (4 x 1 + 2) = 6 3rd term = (2nd term x 2 + 3) = (6 x 2 + 3) = 15 4th term = (3rd term x 3 + 4) = (15 x 3 + 4) = 49 5th term = (4th term x 4 + 5) = (49 x 4 + 5) = 210 and so on. 5 is wrong.