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Find the smallest number by which 392 must be multiplied so that the product is a perfect cube $. (392 = 2 \times 2 \times 2 \times 7 \times 7.)$

Class 8Perfect CubesCubes and Roots

A2
B7
C14
D49

Step-by-Step Solution

392 =

2^{3} \times 7^{2}

. The factor 7 appears twice; one more 7 makes

7^{3}

. So multiply by 7:

392 \times 7 = 2744 = 1 4^{3}

.

Answer: B) 7

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