ABC26GN1439 · Square Roots and Cube Roots

Subject: General Aptitude · Chapter: Square Roots and Cube Roots · Exam: 2005 · Marks: · Difficulty:

If $\sqrt{2}=1.4142$, the value of $\frac{7}{(3+\sqrt{2})}$ is
(a)1.5858
(b)3.4852
(c)3.5858
(d)4.4142
Answer
Answer (as printed): A
Explanation
$\frac{7}{(3+\sqrt{2})}=\frac{7}{(3+\sqrt{2})} \times \frac{(3-\sqrt{2})}{(3-\sqrt{2})}=\frac{7(3-\sqrt{2})}{(9-2)}$ $$=(3-\sqrt{2})=(3-1.4142)=1.5858 .$$

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

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