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:

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 Answer: Option D Explanation: (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.  C.P. of 1 ball = Rs. 720 = Rs. 60. 12