Ratios and proportions 3.4

Writing ratios in fraction form

100

7 to 5

7/5

200

12 to 8

3/2

300

10 to 2

5/1

400

3 1/2 to 5 1/4

2/3

500

3 1/5 to 5 3/10

32/53

Comparing measurements

100

5 gallons to 7 gallons

5/7

200

3 meters to 40 centimeters

15/2

300

200 cents to 3 dollars

2/3

400

30 months to 1 1/2 years

5/3

500

24 ounces to 3 pounds

1/2

Finding a unit price

100

3 pound, 8-ounce box of laundry detergent that sells for 9.49

$ 0.17 per ounce

200

A 20 ounce can of pineapples for $ 0.98 

$ 0.049 per ounce

300

A 12 ounce box of cereal for $ 3.29

$ 0.274 per ounce

400

A 1 pound, 4 ounce loaf of bread for $ 1.46

$ 0.073 per ounce

500

A 1 pound package of cheese for $ 7.49

$ 0.468 per ounce

Comparing unit price

100

What has a lower price? A 13 ounce box of cereal for $ 2.99, or a 18 ounce box of the same cereal for $ 3.79

13 ounce box = $ 0.23 per ounce

18 ounce box = $ 0.21 per ounce

18 ounce box has a lower price per ounce

200

What is lower in price? An 18 ounce jar of peanut butter for $ 1.92, or an 28 ounce jar of peanut butter for $ 3.18

18-ounce jar: $ 0.1067 per ounce

28-ounce jar: $ 0.1136 per ounce

300

What is lower in price? An 11 ounce bag of chocolates for $ 3.29, or an 18 ounce bag of chocolates for $ 5.49

11-ounce bag: $0.2991 per ounce

18-ounce bag: $ 0.3050 per ounce

11 ounce bag is cheaper

400

What is lower in price? A 4 pound bag of sugar for $ 1.89, or a 10 pound bag of sugar for $ 4.49

4-pound bag: $ 0.4725 per pound

For the 10-pound bag: $0.449 per pound 

The 10-pound bag of sugar is cheaper

500

What is lower in price? A gallon of orange juice for $ 6.58, or a half gallon of orange juice for $ 3.49

gallon of orange juice: $6.58 per gallon 

half gallon of orange juice: $6.98 per gallon.

The gallon of orange juice is cheaper

Solving proportions

100

50/x = 2/28

x = 700

200

x-2/5 = 4/3

x = 26/3 

300

Y/25 = 12/10

y = 30

400

X + 1/5 = 3/10

X = 0.5

500

x+6 /3 = x-5 /2

x = 27