Part A
Martha is buying two shirts that each cost $20. at a local store. She is considering two options to purchase the shirts.
Option A: Use the store sale- buy one shirt and get a second shirt at 50% off the original price.
Option B: Use a coupon for 30% off the entire purchase.
Martha will also pay 7% tax on her purchase.
Which option will cost less money?
Option A: Using the store sale, Martha will buy one shirt at full price ($20) and get the second shirt at 50% off. So she will pay $20 + $20/2 = $20 + $10 = $30 for two shirts.
Option B: Using the coupon for 30% off the entire purchase, Martha will get a 30% discount on the total cost of the two shirts. The total cost of the two shirts without any discount is $20 + $20 = $40. So, with the discount, Martha will pay 70% of $40 = 0.7 * $40 = $28 for two shirts.
Now, let's calculate the tax for each option:
Option A: The tax on $30 will be 7% of $30 = 0.07 * $30 = $2.10.
Option B: The tax on $28 will be 7% of $28 = 0.07 * $28 = $1.96.
Finally, let's calculate the total cost for each option:
Option A: $30 (purchase price) + $2.10 (tax) = $32.10.
Option B: $28 (purchase price) + $1.96 (tax) = $29.96.
Therefore, option B will cost less money.