Question

By selling a chair for Rs. 75, Mohan gained as much per cent as its cost. Calculate the cost of the chair.

Answer 1

Let the C.P. of the chair be Rs. x

S.P. of chair = Rs. 75

Profit = Rs. (75 – x)

We know:

Profit% = `"Profit"/("C.P.") xx 100`

∴ `x = (75 - x)/x xx 100`

x² = 7500 – 100x

x² + 100x – 7500 = 0

(x + 150)(x – 50) = 0

x = –150, 50

But, C.P. cannot be negative.

So, x = 50.

Hence, the cost of the chair is Rs. 50