If a=b c and c=a-b, then the value of a is · ABC26GN0987

Subject: General Aptitude · Chapter: Simplification · Exam: R.R.B. 2008

If $a=b c$ and $c=a-b$, then the value of $a$ is

(a)$b^{2}-1$

(b)$\frac{b^{2}}{b-1}$

(c)$\frac{b}{b-1}$

(d)None of these

Answer

Answer (as printed): B

Explanation

$a=b c$ and $c=a-b \Rightarrow a=b(a-b) \Rightarrow a=a b-b^{2}$ $$\Rightarrow b^{2}=a b-a=a(b-1) \Rightarrow a=\frac{b^{2}}{b-1} .$$

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

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