Ratios and Proportions: Master Cross-Multiplication Skills

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

• 5 cups of flour

• 3 cups of flour

• 2 cups of flour

• 4 cups of flour

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

• 30

• 25

• 15

• 20

A map has a scale of 1:100,000. If two cities are 250 km apart, how far apart are they on the map?

• 250 meters

• 5 kilometers

• 1 meter

• 2.5 meters

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

• 180 miles

• 200 miles

• 300 miles

• 240 miles

In a fruit basket, the ratio of apples to oranges is 3:2. If there are 12 apples, how many oranges are there?

• 10

• 4

• 8

• 6

A recipe requires 3 parts of oil for every 2 parts of vinegar. If you have 12 parts of oil, how much vinegar do you need?

• 4 parts of vinegar

• 10 parts of vinegar

• 6 parts of vinegar

• 8 parts of vinegar

The ratio of cats to dogs in a shelter is 7:3. If there are 21 cats, how many dogs are there?

• 6

• 9

• 12

• 15

A school has a ratio of 2 teachers for every 25 students. If there are 100 students, how many teachers are needed?

• 8 teachers

• 10 teachers

• 6 teachers

• 4 teachers

In a painting, the ratio of blue to red paint is 5:3. If you have 15 liters of blue paint, how much red paint do you need?

• 12 liters

• 6 liters

• 15 liters

• 9 liters

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

• 10 gallons

• 8 gallons

• 15 gallons

• 12 gallons