To determine which option will cost less money for Martha, we need to calculate the total cost for each option.
Option A: Buy one shirt and get a second shirt at 50% off
The original price for one shirt is $20. With this option, Martha will pay full price for the first shirt. For the second shirt, she will get 50% off, which is $20 * 50% = $10.
So, the total cost for Option A is $20 + $10 = $30.
Option B: Use a coupon for 30% off the entire purchase
If Martha uses a coupon for 30% off the entire purchase, she will get a discount of 30% * ($20 + $20) = $12.
So, the total cost for Option B is $20 + $20 - $12 = $28.
Now, we need to add 7% tax to each option:
Option A: $30 + 7% tax
Option B: $28 + 7% tax
To compare which option will cost less, we need to calculate the total cost including tax for each option:
Option A: $30 + 7% * $30 = $30 + $2.10 = $32.10
Option B: $28 + 7% * $28 = $28 + $1.96 = $29.96
Therefore, Option B will cost less money for Martha.