Number series – find the wrong term (identify the outlier). Sequence: 56, 72, 90, 110, 132, 150
Aptitude
Odd Man Out and Series
Difficulty: Easy
Choose an option
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A72
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B110
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C132
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D150
Answer
Correct Answer: 150
Explanation
Introduction / Context:This is a difference-pattern series where each step increases by a steadily growing even number. One term breaks the pattern and must be identified.
Given Data / Assumptions:
- Series: 56, 72, 90, 110, 132, 150
- One term is incorrect.
Concept / Approach:Compute successive differences and check whether they follow a simple progression, such as adding even numbers that increase by 2 each time.
Step-by-Step Solution:
72 − 56 = 1690 − 72 = 18110 − 90 = 20132 − 110 = 22Expected next difference is 24, so expected next term = 132 + 24 = 156.Given final term is 150, which is short by 6 and breaks the +2-increment pattern of the differences.Verification / Alternative check:Replace 150 with 156 to obtain differences 16, 18, 20, 22, 24, a consistent arithmetic progression of even numbers.
Why Other Options Are Wrong:
- 72, 110, 132: Each fits perfectly into the growing-difference pattern.
Common Pitfalls:Looking at ratios when the structure is additive. Always test both methods, but here differences immediately reveal the rule.
Final Answer:150