Question

On selling $17$ balls at $\text{Rs.}720$, there is a loss equal to the cost price of $5$ balls. The cost price of a ball is:

• A. $\text{Rs.}45$
• B. $\text{Rs.}50$
• C. $\text{Rs.}55$
• D. $\text{Rs.}60$

Answer 1

The correct option is D $\text{Rs.}60$

Loss $=\text{C.P. - S.P.}$

As per the question,

$\text{(C.P. of 17 balls) - (S.P. of 17 balls) = (C.P. of 5 balls)}$
$\Rightarrow \text{C.P. of 12 balls = S.P. of 17 balls = Rs. 720}$.
$\Rightarrow \text{C.P. of 1 ball}=\text{Rs.}\left(\frac{720}{12}\right)=\text{Rs.}60$.