Ratio, proportion and rates of change

What is the ratio of 24 to 16?

• 3:2

• 2:3

• 4:3

• 2:1

If 5 pencils cost $10, how much do 8 pencils cost at the same rate?

• $16

• $18

• $20

• $22

A car travels 150 miles in 3 hours. What is the speed of the car in miles per hour?

• 45 mph

• 50 mph

• 55 mph

• 60 mph

The ratio of red to blue marbles in a bag is 4:5. If there are 20 red marbles, how many blue marbles are there?

• 25

• 30

• 35

• 40

A recipe calls for 3 cups of flour to 2 cups of sugar. If you use 9 cups of flour, how many cups of sugar should you use?

• 5

• 6

• 7

• 8

If x is directly proportional to y, and y=10 when x=5, what is x when y=20?

• 12

• 10

• 24

• 9

If a car's value depreciates by 15% per year, what will its value be after 2 years if the initial value is $20,000?

• $14,450

• $15,300

• $17,000

• $18,500

In a school, the ratio of boys to girls is 3:4. If there are 120 girls, how many boys are there?

• 80

• 90

• 100

• 110

A worker is paid $12 per hour. If they work for 35 hours a week, how much do they earn in a week?

• $320

• $350

• $400

• $420

The exchange rate is 1 USD = 0.85 EUR. How much is 100 USD in EUR?

• 85 EUR

• 90 EUR

• 95 EUR

• 100 EUR