Discussion of Question with ID = 082 under Square-and-Cube-Roots

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Question

What is √(9720) × √(30)?

A

540.

B

450.

C

496.

D

196.

Soln.
Ans: a

We can see that √(9720) × √(30) is same as √(2 × 2 × 2 × 3 × 3 × 3 × 3 × 3 × 5 ) × √(2 × 3 × 5 ) which equals √(24 × 36 × 52), which equals (22 × 33 × 51), which gives 540.

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