Answer:
(A) Lan should pay $53.79 including sales tax
(B) Lan would now pay $48.41 for the CD player
Step-by-step explanation:
Percentages
Think of a certain product that has a price P. To increase its price a percentage x, we calculate the increase as
[tex]I=P\times x/100[/tex]
Then we add the increase to the original price to get
[tex]P'=P+P\times x/100[/tex]
[tex]P'=P(1+ x/100)[/tex]
The same applies when the price is decreased by an x%
[tex]P'=P(1- x/100)[/tex]
(A) The original price of a CD player was $59.95 and it was on sale for 15% off the price. The new price is
[tex]P'=59.99(1-15/100)[/tex]
[tex]P'=\$50.99[/tex]
Now we must add the 5.5% sales tax
[tex]P''=50.99(1+ 5.5/100)[/tex]
[tex]P''=\$53.79[/tex]
Lan should pay $53.79 including sales tax
(B) One week later, the CD player was reduced by another 10%. The new price was
[tex]P'=50.99(1-10/100)=\$45.89[/tex]
Plus the tax
[tex]P''=\$45.89(1+ 5.5/100)=\$48.41[/tex]
Lan would now pay $48.41 for the CD player
