I got my answer, but this is a really big take home test, and i just want to make sure it's right.
Andrea works as a cashier in a music store. A customer wants to pay for a CD that is on sale for 15% off the regular price of $14.00. The cash register is broken, and Andrea must calculate the price of the CD using only a calculator.
a. What is the sale price of the CD? Show or explain how you got your answer.
b. Andrea needs to add 7% sales tax to the sale price of the CD. What should Andrea charge the customer for the CD, including tax? Show or explain how you got you answer.
c. The customer told Andrea that she could save time by just taking 8% off the regular price of the CD because 15% - 7% is 8%. Is the customer right? Explain your reasoning.
Answers & Comments
Verified answer
a. 15% off means that for $ 100 he has to pay $ 85
so for $14.00 he has to pay 14 × 85/100 = $11.90
b.7% sales tax means for sale of $ 100 he has to pay $ 7 i.e. he has to pay $ 107
so:for $11.90 he has to pay 11.90 × 107/100 = $12.73
c. If ditrct 8% off means the total cost would be 92% of the original price:
$14.00 × 92/100 = 12.88
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a.
15% off means that the customer is only paying 85% of the original price, so:
$14.00 * 85/100 = $11.90
b.
Adding 7% for sales tax means the final cost will be 107% of the sale price, so:
$11.90 * 107/100 = $12.73
c.
No, the customer is wrong. If she had her way, the total cost would be 92% of the original price:
$14.00 * 92/100 = $12.88
This is because percentages are ratios, they are not fixed values that can be added and subtracted like regular numbers.