Question

On selling $17$ balls at Rs.$720$ there is a loss equal to the cost price of $5$ balls. Then what is the cost price of a ball ?

Answer 1

C.P. of $17$ balls $-$S.P. of $17$ balls$=$C.P. of $5$ balls

C.P. of $12$ balls$=$ S.P. of $17$ balls $=$ Rs.$720$.

Hence, C.P. of $1$ ball $=$ Rs.$\frac{720}{12}=$ Rs.$60$.