Answer:
7.5%
Step-by-step explanation:
Cost of memory card including tax = $138.89
Cost of memory card only = $129.20.
Cost of tax on memory card = Cost of memory card including tax - Cost of memory card only
= $138.89 - $129.20
= $9.69
Cost of tax on memory card = $9.69
What percent sales tax did he pay.
Percent of tax = Cost of tax on memory card / Cost of memory card only
= $9.69 / $129.20 × 100
= 0.075 × 100
= 7.5%
Percent of tax = 7.5%
