Complete the series
20, 19, 17, ...., 10, 5

Answer: Option D

Explanation:

In this series, each term is the sum of preceding two terms as,
1+2 = 3
3+2 = 5
5+3 = 8
Next term in the series will be,
8+5 = 13

Answer: Option B

Explanation:

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

Answer: Option D

Explanation:

Numerators of the fractions in the given sequence are getting increased by 2, i.e. 1+2,3+2,5+2, so next will be 7+2 = 9

Denominators of the fractions in the series is getting doubled, 2*2 = 4, 4*2 = 8, 8*2 = 16, no next will be 16*2 = 32

So resulting fraction will be
\begin{aligned}
\frac{9}{32}
\end{aligned}

Answer: Option A

Explanation:

Pattern in the series is *2+1, *2+2, *2+3,.....

Term which replaces the question mark in the series is
121 * 2 + 6 = 248

Answer: Option A

Explanation:

Pattern of the above series is
first + second + 2, second + third + 3, third + fourth + 4......
So next term will be
24 + 41 + 5 = 70