ABC26GN1384 · Square Roots and Cube Roots

Subject: General Aptitude · Chapter: Square Roots and Cube Roots · Exam: · Marks: · Difficulty:

If $\sqrt{.04 \times .4 \times a}=.004 \times .4 \times \sqrt{b}$, then $\frac{a}{b}$ is
(a)$16 \times 10^{-3}$
(b)$16 \times 10^{-4}$
(c)$16 \times 10^{-5}$
(d)None of these
Answer
Answer (as printed): C
Explanation
$$\begin{aligned} & \frac{\sqrt{a}}{\sqrt{b}}=\frac{.004 \times .4}{\sqrt{.04 \times .4}} \Rightarrow \frac{a}{b}=\frac{.004 \times .4 \times .004 \times .4}{.04 \times .4}=\frac{.0000064}{.04} \\ & \Rightarrow \frac{a}{b}=\frac{.00064}{4}=.00016=\frac{16}{10^{5}}=16 \times 10^{-5} . \end{aligned}$$

Explanation as extracted from the printed page; notation may be imperfect.

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