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:	Choices
A) Rs. 20 B) Rs. 60. C) Rs. 40 D) Rs. 30 E) Rs. 90
(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. 720/12 = Rs. 60.   Answer:Rs. 60.
<result>B</result>
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: