Answer: 154

Explanation:
54+12, 66*16, 82*20, 102*24, 126, The difference is increasing by 4, starting with 12. So, the next difference is 24 + 4 = 28 Hence, the next number is 126 + 28 = 154.

Answer: 97 

Explanation:
 7+4 11+9, 20+16, 36 +25, 61 , 146 The differences are
squares of consecutive natural numbers, in increasing
order starting with 2, i.e., 22 = 4. Hence, the next number
in the series is 61 + 36 = 97

Answer: 65

Explanation:
75075 +3, 25025 +5, 5005+7, 716+". , 5.
The numbers are being divided by consecutive prime numbers Hence, the next number in the series is 715 / 11 = 65

Answer: 135

Explanation:
       12 "Ci, 6 6'1S, 92, 18" 45 3

The next number in the series is 45 x 3 - 135.

Answer: 291

Explanation:
12'2"3, 2112"3, 39" 2", 75 2"3, 147, __________________

The next number in the series is 147 7"3- 291.

Answer: 517

Explanation:
5 2+3, 13 2 +3 , 41 2 + 3 , 85 3 + 7, 257 2 + 3, ________
The next number in the series is 257 x 2 + 3 = 517

Answer: 168

Explanation:
440, 360, 288, 224,
= 21^2 – 1, 19^2 – 1, 17^2 – 1, 15^2 – 1, _____
= The given numbers can be expressed in the form of n^2 – 1 of consecutive odd numbers starting from 21^2 – 1. Hence the next number in the series is 13^2 - 1 = 168

Answer: 336

Explanation:
 2^3 - 2, 3^3 - 3, 4^3 – 4, 5^3 – 5, 6^3 – 6, ____
The next number in the series is 7^3 – 7 = 336.

Answer: 21.13 

Explanation:
The given series is an alternate series. The numbers in
the alternate positions starting with 29 in the first
position form a series of consecutive odd numbers in
decreasing order, i.e. 29, 27, 25, 23, 21. The remaining
numbers form a series of prime numbers in
decreasing order starting with 29 i.e. 29, 23, 19,
17,13. Hence, the next two numbers in the series are
21 and 13 respectively.