On selling 11 balls at Rs. 720, there is a loss equal to the cost price of 5 balls. The cost price of a ball is:
Options:
A) s . 45	B) s . 50	C) s . 55	D) s . 60	E) s . 120

Rationale: "( c . p . of 11 balls ) - ( s . p . of 11 balls ) = ( c . p . of 5 balls ) c . p . of 6 balls = s . p . of 11 balls = rs . 720 . c . p . of 1 ball = rs . 720 / 6 = rs . 120 . answer : option e"
Answer: E