Ratios
What is a ratio?
A comparison of two quantities
If a recipe calls for 2 cups of flour for 1 batch of cookies, how many cups of flour do you need for 3 batches?
6 cups
Simplify the ratio 10 : 20 by scaling down.
1 : 2
You have the ratio 6:8. Scale it down to simplest form, then scale it up so the first number is 15. What is the final ratio?
15 : 20
15 to 20
15/20
What is a unit rate?
A rate that compares a quantity to one unit of another quantity
A basket has 4 apples and 6 oranges. What is the ratio of apples to oranges in simplest form?
2 to 3
2 : 3
2/3
Scale up the ratio 4 : 7 so that the first quantity is 20. What is the new ratio?
20 : 35
A batch of 50 cupcakes requires 10 eggs. Scale this down to find how many eggs are needed for 5 cupcakes.
1 egg
A car uses 6 gallons of gas to 120 miles. How far can it travel on 4 gallons of gas?
80 miles
If you pay $12 for 3 notebooks. What is the unit price per notebook?
$4 per notebook
A class has 12 boys and 15 girls. What is the ratio of girls to the total number of students in simplest form?
5 to 9
5 : 9
5/9
60 miles
Scale down the ratio 36 to 24 so that the second number becomes 2. What is the scaled-down ratio?
3 to 2
3 : 2
3/2
If 8 boxes of cereal cost $24, how much does 5 boxes of cereal cost?
$15
A cyclist travels 45 miles in 3 hours. What is their unit speed in miles per hour (mph)?
15 miles per hour
Which of the following ratios is NOT equivalent to 3:4?
a) 6:8
b) 9:12
c) 12:15
d) 15:20
c) 12:15
An artist mixes 3 parts red paint with 5 parts yellow paint. If she scales the mix up to use 25 parts of yellow paint, how many parts of red paint does she need?
15 parts red paint
A factory produces 120 toys in 8 hours. Scale Down to find how many toys they make in 2 hours.
30 toys
A recipe using 12 cups of milk makes 30 pancakes. How many cups of milk are needed to make 20 pancakes?
8 cups
Store A sells a 6-pack of juice for $4.50. Store B sells a 4-pack of the same juice for $3.20. Which store offers the better unit rate?
Store A ($0.75 per bottle vs. Store B $0.80 per bottle)
In a garden, the ratio of roses to tulips is 3 to 5. If there are 40 flowers in total, how many are roses?
15 roses
A runner covers 2 miles in 14 minutes. Keeping the same pace, how many minutes will it take them to run 7 miles?
49 minutes
A large park has a tree-to-bench ratio of 45:18. Scale down this ratio to its simplest form.
5 : 2
5 to 2
5/2
15 workers can build 3 sheds in a week. How many workers are needed to build 5 sheds in the same timeframe?
25 workers
4 gallons per minute