Question

The cost of a pen is $Rs.15$. If its cost decreases by $Rs.x$ then the number of pens purchased of $Rs.600$ is _______.

• A. $\frac{600}{15+x}$
• B. $\frac{600}{15-x}$
• C. $\frac{15-x}{600}$
• D. $\frac{15+x}{600}$

Answer 1

Answer: (B)

$\frac{600}{15-x}$

The cost of a pen is $Rs.15$.
Its cost decreases by $Rs.x$.
Then new cost of pen is $Rs.(15-x)$
$Rs(15-x):1pen$
$Rs.600:(?)$
$⟹\frac{600}{15-x}pens$.

Hence option $\left(B\right)$ is correct