Equation of Proportionality

Caylee wants to buy pencils printed with the school mascot. The cost of 100 pencils is $12. Which of the following represents the equation for the cost (c) per pencil (p)?

• c = 8.3p

• c = 0.12p

• 100p = 12c

• p = 0.12c

The graph below shows the amount of money Johnny saved $168 for 12 months. Which equation would help determine Johnny’s balance,b, for a certain number of months, m?

• b = 7.14m

• 168d = 12m

• b = 1/14m

• b = 14m

Ammonie used a table to record how far and how much time she rode her bicycle. What equation could she use to determine how many miles she would ride, m , if she traveled any number of hours, h?

• m = 15.5h

• 3h = 42m

• m = 14h

• h = 14m

Four customers at a gas station this morning each purchased the same type of gasoline. The table below shows the amounts of gasoline they purchased and the costs. What equation shows the total cost it would be, C, for, n, gallons of this type of gasoline?

• C = 0.25n

• C = 1/4n

• C = 3n

• C = 4n

The value of y is proportional to x. When x = 3 then y = 15. Which equation represents the relationship between x and y?

• y = 0.2x

• y = 5x

• y = 12x

• 15y = 3x

Michelle bought the same fabric on 3 different occasions and recorded the data in the table below. What equation could be used to determine the total cost,C, of any amount of fabric, f?

• 2.2F = 2.53C

• C = 1.15f

• F = 1.05c

• F = 1.15c

For every 10 apples gathered from trees in an orchard, there are 9 apples that are good to sell. Which equation determines the constant relationship between s, the number of apples good to sell and, g ,the number of apples gathered?

• s = 1.1 g

• s = 0.9g

• g = s - 1

• 10g = 9s

The table shows the total amount of food that was collected in a community in a certain number of weeks. What equation could be used to figure out the amount of food in pounds, P, that could be collected after any number of weeks, w?

• W = 8.9p

• 4w = 35.6p

• P = 8.9w

• P = .11w

Unique can make 1/8 quart of orange juice in 3/4 of a minute by squeezing oranges. At this rate, how much juice can she make in 1 minute?

• 3/32 quart

• 1/6 quart

• 1/2 quart

• 6 quarts

You spend $40 on 5 pounds of concrete. What is the unit rate in dollars per pound?

• $8 per pound
• $5 per pound
• $35 per pound
• 0.125 pounds per dollar