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:	Select.
A) Rs. 45
B) Rs. 50
C) Rs. 55
D) Rs. 60
E) Rs. 60
(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: Option Rs. 60
<result>D</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: