Question & Answer

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.60
D. Rs.55

ANSWER Verified Verified
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.

Complete step-by-step answer:
Let the C.P. of a ball = x.
Then, the C.P. of 17 balls = 17x
and C.P of 5 balls = 5x
S.P of 17 balls = 720
Then according to the question, we can make the equation as:
$ \Rightarrow $17x − 720 = 5x as (Loss = C.P - S.P)
$ \Rightarrow $12x = 720
$ \Rightarrow $ x = $ \dfrac{720}{12}$ = 60
Hence, the cost price of the ball is Rs.60.

Note – In this problem you have to assume variables for the cost price and make equations according to the information provided in the problem. We have subtracted 720 because the difference in cost price and selling price is loss. Proceeding with this we have done this answer correct.