Answer:
a) marked-down price = $6.00
b) with-tax cost = $6.06
Step-by-step explanation:
a) The amount of the markdown is ...
0.20 × $7.50 = $1.50
so the marked-down price is ...
$7.50 - 1.50 = $6.00
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b) The sales tax is ...
0.01 × $6.00 = $0.06
so the total cost with tax is ...
$6.00 + 0.06 = $6.06
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Of course, you know that 20% = 20/100 = 0.20, and 1% = 1/100 = 0.01.