Proportional Relationships and Percentages Review

What is the formula for calculating percent change?

• New Value + Old Value / Old Value

• New Value - Old Value / New Value

• New Value * Old Value / 100

• ((New Value - Old Value) / Old Value) * 100

Aria had 50 apples. After a fruitful harvest, she now has 70 apples. Calculate the percent change in the number of apples Aria has.

• 40%

• 10%

• 20%

• 50%

Jackson, Evelyn, and Priya were working on a project in their physics class. They were asked to measure the length of their classroom's table. Jackson measured the length as 120 cm, but the actual length was 125 cm. Calculate the percent error in Jackson's measurement.

• 2%

• 4%

• 10%

• 6%

A car travels 300 miles in 5 hours. What is the constant of proportionality in the equation relating distance and time?

• 60

• 100

• 50

• 200

Grace is baking a cake. The recipe calls for 2 cups of flour and 3 cups of sugar. If 'f' represents the amount of flour and 's' represents the amount of sugar, what equation represents the relationship between the flour and sugar Grace uses?

• f = 1.5s

• f = 2/3s

• f = 2s

• f = 3s

Avery is selling lemonade at a stand. If Avery earns $15 when she sells 5 cups of lemonade, write an equation to represent this situation.

• y = 10x

• y = 3x

• y = 5x

• y = 20x

David had 80 apples. He gave some to Grace and Aria, and now he has 60 apples. What is the percent change in the number of apples David has?

• 25%

• 20%

• 30%

• 15%

Write an equation for the following situation: y = 20 when x = 4.

• y = 5x

• y = 4x

• y = 6x

• y = 3x

William, Evelyn, and Michael are on a train journey. The train travels 450 miles in 3 hours. If the train maintains a constant speed, what is the speed of the train?

• 150 miles per hour

• 200 miles per hour

• 100 miles per hour

• 50 miles per hour

A store is offering a 20% discount on a shirt that originally costs $50. How much will the shirt cost after the discount?

• $40

• $30

• $35

• $45