Part A) Divide 3 over 18.99 and we get 3/18.99 = 0.15798 approximately. So for this choice, we have roughly a 15.798% discount
Part B) The discount here is 10%. So far, discount A is better
Part C) The discount here is 15%. Discount A is also better because 15.798% is larger than 15%
Part D) Convert 1/4 to decimal form to get 0.25 and then move the decimal point 2 spots to the right to get 25%. So 1/4 = 25%. The discount here is 25%. This discount (of 25%) is much better than discount A.
Store 5 has the best discount since 25% is the largest among all the percentages.
Answer: Choice D)