Question:medium

Find the odd word from the given alternatives.

Updated On: May 6, 2026
  • 728
  • 512
  • 343
  • 216
  • 125
Show Solution

The Correct Option is A

Solution and Explanation

Step 1: Understanding the Question:
We need to find the number that does not follow the mathematical pattern shared by the other four numbers.
Step 2: Detailed Explanation:

Analyzing the numbers:
- \(125 = 5 \times 5 \times 5 = 5^3\) (It is a perfect cube)
- \(216 = 6 \times 6 \times 6 = 6^3\) (It is a perfect cube)
- \(343 = 7 \times 7 \times 7 = 7^3\) (It is a perfect cube)
- \(512 = 8 \times 8 \times 8 = 8^3\) (It is a perfect cube)

Analyzing 728:
The next perfect cube after \(8^3\) is \(9^3 = 9 \times 9 \times 9 = 729\).
The number provided is 728, which is \(729 - 1\) or \(9^3 - 1\).

Conclusion: Numbers 125, 216, 343, and 512 are all exact perfect cubes of consecutive integers (5, 6, 7, and 8). Number 728 is not a perfect cube; it is one less than a perfect cube.

Step 3: Final Answer:
728 is the odd one out because it is not a perfect cube.
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