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:________? February 2, 2020 – by admin 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. 55D. Rs. 60