Odd man out and series

(81) Which number does not belong in the series: 6, 9, 12, 15, 18, 22, 25?

• (a) 12
• (b) 15
• (c) 18
• (d) 22

Answer

Correct Answer: (d) 22
The pattern is adding 3 to each number: 6, 9, 12, 15, 18, 21, 24, …
The number 22 does not fit this pattern.

(82) Look at this series: 4, 7, 12, 19, 28, … What number should fill the blank?

• (a) 35
• (b) 38
• (c) 30
• (d) 39

Answer

Correct Answer: (d) 39
This is a series where each number increases by 3 more than the previous increment: 4, 4+3, 7+5, 12+7, 19+9, …
The next number should be \(28+11 = 39\).

(83) Which number does not belong in the series: 2, 6, 12, 20, 30, 42, 56?

• (a) 12
• (b) 20
• (c) 30
• (d) 56

Answer

Correct Answer: (d) 56
The pattern is adding consecutive even numbers: 2, 4, 6, 8, 10, 12, …
The number 56 does not fit this pattern.

(84) Look at this series: 1, 2, 6, 24, 120, … What number should fill the blank?

• (a) 360
• (b) 720
• (c) 240
• (d) 720

Answer

Correct Answer: (d) 720
This is a series of numbers where each number is multiplied by the next positive integer: 1, 1×2, 2×3, 6×4, 24×5, …
The next number should be \(120×6 = 720\).

(85) Which number does not belong in the series: 5, 11, 23, 47, 95, 191, 383?

• (a) 23
• (b) 47
• (c) 95
• (d) 383

Answer

Correct Answer: (d) 383
The pattern is doubling each number and then subtracting 1: 5, 5×2-1, 11×2-1, 23×2-1, 47×2-1, …
The number 383 does not fit this pattern.