ABC26GN1653 · Problems on Numbers

Subject: General Aptitude · Chapter: Problems on Numbers · Exam: 2010 · Marks: · Difficulty:

If a number is multiplied by two-thirds of itself the value so obtained is 864 . What is the number?

(a)34

(b)36

(c)38

(d)44

(e)46

Answer

Answer (as printed):

Explanation

Let the number be $x$. Then, $x \times \frac{2}{3} x=864$ $$\begin{aligned} & \Leftrightarrow \frac{2}{3} x^{2}=864 \\ & \Leftrightarrow x^{2}=\left(\frac{864 \times 3}{2}\right)=1296 \Leftrightarrow x=\sqrt{1296}=36 . \end{aligned}$$

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

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