# Number Series: Exercise-1

#### Overview:

 Questions and Answers Type: MCQ (Multiple Choice Questions). Main Topic: Verbal Reasoning. Verbal Reasoning Sub-topic: Number Series Questions and Answers. Number of Questions: 10 Questions with Solutions.

Directions: What should come in place of the question mark (?) in the following number series.

1. 8, 11, 14, 17, 20, ?

1. 21
2. 22
3. 23
4. 24

Solution: Add +3 with every term, as given below. $$8 \overset{+3}{\longrightarrow}\ 11 \overset{+3}{\longrightarrow}\ 14 \overset{+3}{\longrightarrow}\ 17 \\ \overset{+3}{\longrightarrow}\ 20 \overset{+3}{\longrightarrow}\ \boxed{23}$$

1. 2.5, 5, 7.5, 10, ?

1. 11.5
2. 12
3. 12.5
4. 13

Solution: Add +2.5 with every term, as given below. $$2.5 \overset{+2.5}{\longrightarrow}\ 5 \overset{+2.5}{\longrightarrow}\ 7.5 \overset{+2.5}{\longrightarrow}\ 10 \\ \overset{+2.5}{\longrightarrow}\ \boxed{12.5}$$

1. 3, 4, 7, 12, 19, ?

1. 25
2. 26
3. 27
4. 28

Solution: Add odd numbers (1, 3, 5, 7, 9) with every term, as given below. $$3 \overset{+1}{\longrightarrow}\ 4 \overset{+3}{\longrightarrow}\ 7 \overset{+5}{\longrightarrow}\ 12 \\ \overset{+7}{\longrightarrow}\ 19 \overset{+9}{\longrightarrow}\ \boxed{28}$$

1. 15, 13, 11, 9, 7, ?

1. 5
2. 4
3. 3
4. 2

Solution: Subtract -2 with every term, as given below. $$15 \overset{-2}{\longrightarrow}\ 13 \overset{-2}{\longrightarrow}\ 11 \overset{-2}{\longrightarrow}\ 9 \\ \overset{-2}{\longrightarrow}\ 7 \overset{-2}{\longrightarrow}\ \boxed{5}$$

1. 30, 22, 18, 16, ?

1. 12
2. 13
3. 14
4. 15

Solution: Follow the sequence given below. $$30 \overset{-8}{\longrightarrow}\ 22 \overset{-4}{\longrightarrow}\ 18 \overset{-2}{\longrightarrow}\ 16 \\ \overset{-1}{\longrightarrow}\ \boxed{15}$$

1. 3, 5, 9, 17, 33, ?

1. 43
2. 53
3. 62
4. 65

Solution: Follow the sequence given below. $$3 \overset{+2}{\longrightarrow}\ 5 \overset{+4}{\longrightarrow}\ 9 \overset{+8}{\longrightarrow}\ 17 \\ \overset{+16}{\longrightarrow}\ 33 \overset{+32}{\longrightarrow}\ \boxed{65}$$

1. 18, 23, 20, 25, 22, ?

1. 24
2. 26
3. 27
4. 28

Solution: Follow the sequence given below. $$18 \overset{+5}{\longrightarrow}\ 23 \overset{-3}{\longrightarrow}\ 20 \overset{+5}{\longrightarrow}\ 25 \\ \overset{-3}{\longrightarrow}\ 22 \overset{+5}{\longrightarrow}\ \boxed{27}$$

1. 25, 26, 28, 31, 35, ?

1. 36
2. 38
3. 40
4. 42

Solution: Follow the sequence given below. $$25 \overset{+1}{\longrightarrow}\ 26 \overset{+2}{\longrightarrow}\ 28 \overset{+3}{\longrightarrow}\ 31 \\ \overset{+4}{\longrightarrow}\ 35 \overset{+5}{\longrightarrow}\ \boxed{40}$$

1. 55, 45, 36, 28, 21, ?

1. 18
2. 17
3. 16
4. 15

Solution: Follow the sequence given below. $$55 \overset{-10}{\longrightarrow}\ 45 \overset{-9}{\longrightarrow}\ 36 \overset{-8}{\longrightarrow}\ 28 \\ \overset{-7}{\longrightarrow}\ 21 \overset{-6}{\longrightarrow}\ \boxed{15}$$

1. 2, 5, 10, ?, 26.

1. 15
2. 16
3. 17
4. 18

Solution: Follow the sequence given below. $$2 \overset{+3}{\longrightarrow}\ 5 \overset{+5}{\longrightarrow}\ 10 \overset{+7}{\longrightarrow}\ \boxed{17} \overset{+9}{\longrightarrow}\ 26$$