Discussion of Question with ID = 032 under Square-and-Cube-Roots

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Question

If $2√3 + √27 = 8.66$, then what is the value of $√27 + 4√3$?

A

12.12.

B

12.24.

C

12.00.

D

12.36.

Soln.
Ans: a

The given expression can be rearranged like this: $2√3 + √{3^{2} × 3}$, which is same as $2√3 + 3√3$ which is same as $5√3 = 8.66$, from which we get $√3 = 1.73$. Next we can see that $√27 + 4√3$ is same as $√{3^{2} × 3} + 4√3$, which is same as $7√3$, which gives $7 × 1.73$ = 12.12.

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