Number Series: Exercise-5

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: In each of the following questions, one number is wrong in the series. Find out the wrong number.


  1. 1, 3, 7, 13, 21, 33

    1. 33
    2. 21
    3. 13
    4. 3


Answer: (a) 33

Solution: Follow the sequence given below. $$ 1 \overset{+2}{\longrightarrow}\ 3 \overset{+4}{\longrightarrow}\ 7 \overset{+6}{\longrightarrow}\ \\ 13 \overset{+8}{\longrightarrow}\ 21 \overset{+10}{\longrightarrow}\ \boxed{31} $$

  1. 2, 4, 16, 98, 768

    1. 768
    2. 98
    3. 16
    4. 4


Answer: (b) 98

Solution: Follow the sequence given below. $$ 2 \overset{\times 2}{\longrightarrow}\ 4 \overset{\times 4}{\longrightarrow}\ 16 \overset{\times 6}{\longrightarrow}\ \\ \boxed{96} \overset{\times 8}{\longrightarrow}\ 768 $$

  1. 5, 6, 9, 12, 21, 30

    1. 9
    2. 12
    3. 21
    4. 30


Answer: (b) 12

Solution: Follow the sequence given below. $$ 5 \overset{+1}{\longrightarrow}\ 6 \overset{+3}{\longrightarrow}\ 9 \overset{+5}{\longrightarrow}\ \\ \boxed{14} \overset{+7}{\longrightarrow}\ 21 \overset{+9}{\longrightarrow}\ 30 $$

  1. 36, 20, 14, 16, 23.5

    1. 20
    2. 14
    3. 16
    4. 23.5


Answer: (c) 16

Solution: Follow the sequence given below. $$ 36 \overset{\div 2 + 2}{\longrightarrow}\ 20 \overset{\div 2 + 4}{\longrightarrow}\ 14 \overset{\div 2 + 8}{\longrightarrow}\ \\ \boxed{15} \overset{\div 2 + 16}{\longrightarrow}\ 23.5 $$

  1. 4, 6, 14, 42, 178

    1. 178
    2. 42
    3. 14
    4. 6


Answer: (b) 42

Solution: Follow the sequence given below. $$ 4 \overset{\times 1 + 2}{\longrightarrow}\ 6 \overset{\times 2 + 2}{\longrightarrow}\ 14 \overset{\times 3 + 2}{\longrightarrow}\ \\ \boxed{44} \overset{\times 4 + 2}{\longrightarrow}\ 178 $$

  1. 2, 12, 58, 172, 178

    1. 178
    2. 172
    3. 58
    4. 12


Answer: (a) 178

Solution: Follow the sequence given below. $$ 2 \overset{\times 7 - 2}{\longrightarrow}\ 12 \overset{\times 5 - 2}{\longrightarrow}\ 58 \overset{\times 3 - 2}{\longrightarrow}\ \\ 172 \overset{\times 1 - 2}{\longrightarrow}\ \boxed{170} $$

  1. 5, 4, 9, 15, 56

    1. 4
    2. 9
    3. 15
    4. 56


Answer: (b) 9

Solution: Follow the sequence given below. $$ 5 \overset{\times 1 - 1}{\longrightarrow}\ 4 \overset{\times 2 - 2}{\longrightarrow}\ \boxed{6} \overset{\times 3 - 3}{\longrightarrow}\ \\ 15 \overset{\times 4 - 4}{\longrightarrow}\ 56 $$

  1. 5, 7, 9, 6, 5

    1. 5
    2. 7
    3. 6
    4. 9


Answer: (c) 6

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

  1. 18, 17, 18, 15, 18

    1. 18
    2. 17
    3. 15
    4. None of these


Answer: (c) 15

Solution: Follow the sequence given below. $$ 18 \overset{-1}{\longrightarrow}\ 17 \overset{+1}{\longrightarrow}\ 18 \overset{-2}{\longrightarrow}\ \\ \boxed{16} \overset{+2}{\longrightarrow}\ 18 $$

  1. 84, 44, 24, 12, 9

    1. 44
    2. 24
    3. 12
    4. 9


Answer: (c) 12

Solution: Follow the sequence given below. $$ 84 \overset{\div 2 + 2}{\longrightarrow}\ 44 \overset{\div 2 + 2}{\longrightarrow}\ 24 \overset{\div 2 + 2}{\longrightarrow}\ \boxed{14} \\ \overset{\div 2 + 2}{\longrightarrow}\ 9 $$