A shopkeeper allows a discount of 10% on the marked price. How much above the cost price must he mark his goods to gain 8%?
I assume cost price to be P. So the shopkeeper must get 1.08P to make a profit of 8%. He allows a discount of 10%. I am told that 90% of marked price is 1.08P because the shopkeeper offers a discount of 10%. Can somebody please explain why 90% of marked price is 1.08P?