Musa paid sh 180 for a shirt after getting a discount of 10%.The shopkeeper made a profit of 20% on the sale of this shirt.What percentage profit would the shopkeeper have made if no discount was allowed?.
Let's find out how much Musa initially paid before the discount was applied.
If Musa got a discount of 10%, it means he paid 100% - 10% = 90% of the original price.
So, 90% of the original price is equal to 180 shillings.
Let x be the original price of the shirt.
Then, 0.90*x = 180.
Dividing both sides of the equation by 0.90, we get x = 200 shillings.
Now, let's calculate the profit made by the shopkeeper when no discount was allowed.
If the shopkeeper sold the shirt for 200 shillings and made a 20% profit, it means the selling price was 100% + 20% = 120% of the cost price.
Thus, the selling price was (120/100)*200 = 240 shillings.
Hence, the shopkeeper would have made a 240 - 200 = <<240-200=40>>40 shilling profit.
To calculate the profit percentage, we divide the profit by the cost price and multiply by 100%:
Profit percentage = (40/200) * 100% = 20%. Answer: \boxed{20}.