Question

a tradman marks his goods at 25% above cost price if he allow his customer 10% discount how much percent profit does he make

Answer 1

profit=12.5% is your ans.

Answer 2

Let the cost price of the article by tradesman = Rs x
He marked at 25% above cost price.
Therefore marked price = x + 25% of x
                                         = x + 25/100*x
                                         = x + x/4 
                                         = Rs 5x/4
Now he gave dicount on this price for a customer
Now price after discount = 5x/4 - 10% of 5x/4
                                          = 5x/4 - 10/100*5x/4
                                          = 5x/4 - 5x/40
                                          = 50x - 5x / 40 
                                          = Rs 45x/40
Therefore Rs 45x/40 is the selling price of trader.
Profit of trader = S.P - C.P
                         = Rs 45x/40 - Rs x
                         = Rs 5x/40
                         = Rs x/8
Profit% = profit/C.P * 100
             = (x/8)/x * 100
             = x/8 * 1/x * 100
             = 100/8
             = 12.5 %
The profit% of trader = 12.5 %