If they increase 40% the answer would be $20.99 , if they make a discount of 40% the answer would be $8.99 . You just find 10% of 14.99 which is 1.5 , you move the decimal to the left once and you round your answer . Then you multiply 1.5 times 4 =6 . Then you add that to 14.99 if 40% is increasing or you subtract it if there is a discount of 40%.