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


Answer: (c) 23

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


Answer: (c) 12.5

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


Answer: (d) 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


Answer: (a) 5

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


Answer: (d) 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


Answer: (d) 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


Answer: (c) 27

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


Answer: (c) 40

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


Answer: (d) 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


Answer: (c) 17

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