ABC26GN1433 · Square Roots and Cube Roots

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

Given $\sqrt{5}=2.2361, \sqrt{3}=1.7321$, then $\frac{1}{\sqrt{5}-\sqrt{3}}$ is equal to
(a)1.98
(b)1.984
(c)1.9841
(d)2
Answer
Answer (as printed): C
Explanation
$\frac{1}{(\sqrt{5}-\sqrt{3})}=\frac{1}{(\sqrt{5}-\sqrt{3})} \times \frac{(\sqrt{5}+\sqrt{3})}{(\sqrt{5}+\sqrt{3})}=\frac{(\sqrt{5}+\sqrt{3})}{(5-3)}$ $$=\frac{(2.2361+1.7321)}{2}=\frac{3.9682}{2}=1.9841 .$$

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

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