Mastering Ratios: Proportions and Cross-Multiplication

A recipe calls for 2 cups of flour for every 3 cups of sugar. If you have 6 cups of sugar, how many cups of flour do you need?

• 4 cups of flour

• 6 cups of flour

• 2 cups of flour

• 3 cups of flour

A car travels 150 miles on 5 gallons of gas. How many miles can it travel on 8 gallons of gas?

• 180 miles

• 240 miles

• 300 miles

• 200 miles

In a class, the ratio of boys to girls is 4:5. If there are 20 boys, how many girls are there?

• 20

• 15

• 30

• 25

A map shows that 1 inch represents 10 miles. If two cities are 3 inches apart on the map, how far apart are they in real life?

• 15 miles

• 20 miles

• 30 miles

• 25 miles

A fruit stand sells apples and oranges in the ratio of 3:2. If there are 30 apples, how many oranges are there?

• 25

• 15

• 20

• 10

A recipe requires 4 eggs for every 2 cups of milk. How many eggs are needed for 5 cups of milk?

• 10 eggs

• 6 eggs

• 8 eggs

• 12 eggs

If 5 notebooks cost $15, how much would 8 notebooks cost?

• $30

• $18

• $24

• $20

A car can travel 240 miles on 6 gallons of gas. How many gallons are needed to travel 400 miles?

• 12 gallons

• 10 gallons

• 8 gallons

• 15 gallons

In a school, the ratio of teachers to students is 1:20. If there are 300 students, how many teachers are there?

• 15

• 20

• 25

• 10

A painter mixes blue and yellow paint in the ratio of 2:3. If he uses 10 cups of blue paint, how many cups of yellow paint does he need?

• 5 cups

• 10 cups

• 15 cups

• 20 cups