A boy sold his cap for Rs. 24 and got a profit percentage numerically equal to the cost price. What will be the cost price of the cap?
A boy sold his cap for Rs. 24 and got a profit percentage numerically equal to the cost price. What will be the cost price of the cap? Correct Answer Rs. 20
Given
The selling price of cap = Rs 24
Formula Used
Cost price = {Selling Price/(100 + profit%)} × 100
Calculation
Let the cost price be x
⇒ x = 24/(100 + x) × 100
⇒ x2 + 100x - 2400 = 0
⇒ x2 + 120x - 20x - 2400 = 0
⇒ x(x + 120) - 20(x + 120) =
⇒ (x - 20)( x + 120)
We get x = 20 and x = - 120
(As cost price cannot be negitive)
So, cost price = Rs 20
∴ The cost price is Rs 20
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Feb 20, 2025