What is the smallest number by which 392 must be multiplied so that the product is a perfect cube?

By Team Aakash Byju's | 23rd January 2023

The correct answer is 7.

Brief Explanation

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A number can be said to be perfect if all its prime factors can be cubed. So, to check if 392 is a perfect cube or not, let us find its prime factors.

392 = (2×2×2) × (7×7)

=> 392 = (2)  × (7)

3

2

Since each prime factor must have a power of 3 to make the given number a perfect cube.

 we need to multiply 392 by 7.

=> 392×7 = 2  × 7  × 7

2

3

=> 2744 = 2  × 7

3

3

=> √(2744) = 14

3

Thus, multiplying 392 by 7 results in a number that is a perfect cube.