QUESTION

# 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.45B. Rs.50C. Rs.60D. Rs.55

Hint – In order to solve this problem we need to assume the cost price as a variable and then make an equation according to the problem and solve this problem.

$\Rightarrow$17x − 720 = 5x as (Loss = C.P - S.P)
$\Rightarrow$12x = 720
$\Rightarrow$ x = $\dfrac{720}{12}$ = 60