1) On selling 17 balls at Rs. 720, there is a loss equal to the cost price of 5 balls. The cost price of a ball is : A) Rs. 45 B) Rs. 50 C) Rs. 55 D) Rs. 60 E) Rs. 70 Answer: Option DExplanation:(C.P of 17 balls) - (S.P of 17 balls) = (C.P of 5 balls) $\Rightarrow$ C.P of 12 balls = S.P of 17 balls = Rs. 720. $\Rightarrow$ C.P of 1 ball = Rs. $\left(\frac{720}{12}\right)$ = Rs. 60.
