Odd man out and series

(36) Which number does not belong in the series: 3, 6, 9, 12, 15, 19, 24?

• (a) 9
• (b) 19
• (c) 12
• (d) 24

Answer

Correct Answer: (b) 19
The pattern is adding 3 to each number: 3, 6, 9, 12, 15, 18, 21, …
The number 19 does not fit this pattern.

(37) Look at this series: 5, 10, 20, 40, 80, … What number should fill the blank?

• (a) 100
• (b) 120
• (c) 160
• (d) 160

Answer

Correct Answer: (d) 160
This is a series of doubling numbers: 5, 10, 20, 40, 80, …
The next number should be \(80 \times 2 = 160\).

(38) Which number does not belong in the series: 18, 27, 36, 45, 54, 63, 72?

• (a) 27
• (b) 45
• (c) 54
• (d) 63

Answer

Correct Answer: (b) 45
The pattern is adding 9 to each number: 18, 27, 36, 45, 54, 63, 72, …
The number 45 does not fit this pattern.

(39) Look at this series: 2, 5, 10, 17, 26, … What number should fill the blank?

• (a) 33
• (b) 36
• (c) 41
• (d) 37

Answer

Correct Answer: (d) 37
The pattern is adding consecutive prime numbers: 3, 5, 7, 11, 13, 17, 19, …
The next number should be \(26 + 11 = 37\).

(40) Which number does not belong in the series: 8, 12, 16, 20, 24, 30, 36?

• (a) 12
• (b) 20
• (c) 24
• (d) 30

Answer

Correct Answer: (d) 30
The pattern is adding 4 to each number: 8, 12, 16, 20, 24, 28, 32, …
The number 30 does not fit this pattern.