Day 8 percents and total cost web

We often have to add or subtract percentagesto find the total cost... Every Tuesday, the movie theater offers a 20% discount on tickets purchased for the evening movies.. If you use this

We often have to add or subtract percentages

to find the total cost.

• Examples of percents that add to the cost

– Tip, or gratuity

– Tax

– Interest

– Mark-up

• Examples of percents that subtract from the cost

– Discount

– Coupon

– Sale

– Mark-down

Ex 2) A movie ticket is regularly priced at $9.50

Every Tuesday, the movie theater offers a 20%

discount on tickets purchased for the evening

movies If you use this discount, what is the sale

price of a movie ticket?

Sale price = price - discount

whole

part 100

percent =

90 1

$

50 9

100 20

=

=

x

x

Find the discount

Subtract the discount from the

regular price to find the sale price Sale price = $9.50 - $1.90Sale price = $7.60

The sale price of a movie ticket is $7.60.

Ex 1) A new soccer ball is priced at

$37 If the sales tax is 8%, what is the total cost to buy the soccer ball?

Total cost = price + tax

whole

part 100

percent =

96 2

$

37

100 8

=

=

x

x

Find the tax

Add the price and the tax to

find the total cost Total cost = $37 + $2.96

Total cost = $39.96

The soccer ball costs $39.96 including tax.

Ex 4) A group of friends went to lunch The bill,

before sales tax and tip was $37.50 A sales tax of

8% was added The group then tipped 18% on the

amount after the sales tax was added

a)What was the amount, in dollars of the sales

tax?

b)What was the total amount the group paid,

including tax and tip?

Part = Percent (Whole) Part

Part = 0.08 (37.5) Part = 3

The tax for the lunch was $3.

Total = bill + tax

Total = 37.50 + 3

Total = 40.50

Part = Percent (Whole) Total amount = total + tip Total = 40.50 + 7.29

Total = 47.79 The total amount the group paid including tax and tip was $47.79.

Ex 4) The Moore family wants to buy a new computer

regularly priced at $1,049 Mrs Moore has a coupon

for 20% off any item in the store

a)How much will the computer cost if they use the

coupon?

b)What is the total amount the Moore family paid

after the sales tax of 8% was included?

The price of the computer with the coupon is

$839.20.

The price of the computer

including tax is

$906.34.

Part = Percent (Whole)

Part = Percent (Whole)

Cost = Price – Discount Cost = 1049 – 209.80 Cost = 839.20

Total = Cost + Tax Total = 839.20 +6714 Total = 906.34