20, 19, 17, (...) , 10, 5

Answer: Option A

Explanation:

Please look carefully at the series, its pattern is,
-1, +2, -1, +2, -1, so next will be +2
23+2 = 25

Answer: Option B

Explanation:

Pattern is, +4, +8, +16, +32, so next will be +64
81+64 = 145

Answer: Option A

Explanation:

Pattern in the series is, -2, -4, -2, -4. So next term will be -2
24 -2 = 22

Answer: Option D

Explanation:

Please check that given sequence consists of two series

Series 1: 5, 7, 10, 14
Series 2: 6, 8, 11, ...

In series 2 pattern is +2, +3, Next will be +4
So required number in the series will be 11+4 = 15

Answer: Option B

Explanation:

Pattern is , +5, +7, +9
Missing Number = 19+9 = 28