Understanding Rates & Unit Rate (Activity 19 Springboard)

A factory can produce mousetraps at a rate of 1,500 traps in 3 hours. What is the unit rate per hour?

A factory that produces toy wheels finds that they must discard 3 out of every 100 wheels because they are defective. How many wheels would they expect to discard every day if the factory produces 1,200 wheels per hour in each 8-hour day?

A mousetrap car is filmed as it runs the racecourse. The film includes 1,200 photo frames taken in 8 seconds. How many frames were taken in one second? Justify your answer.

Last year, one science teacher spent $65.50 to buy materials for the Mousetrap Car event. If 12 students participated in the event, what was the teacher's unit cost per student?

• A. $2.98

• B. $6.55

• C. $5.46

• D. $7.86

Mr. Walker, the contest sponsor, bought toy wheels in a package of 6 dozen for $81.00. What was the unit cost of each wheel?

• A. $1.125

• B. $1.50

• C. $6.75

• D. $13.50

Mr. Walker wrote notes about the event that would help him plan for the following year. If he will still purchase 8 traps per person, how many traps will he need to purchase for 25 people in the Mousetrap Car race?

• A. 4

• B. 8

• C. 200

• D. 400

A meatball recipe has a ratio of 2 cups of breadcrumb mixture to 3 pounds of ground meat. How much breadcrumb mixture is there for 1 pound of ground meat?

The table shows rates for the cost of buying model rocket packages. What is the unit rate for each of the XYZ Toys model shown?

The table shows rates for the cost of buying model rocket packages. What is the unit rate for each of the AAA Science Supply model shown?

PVC pipe used to make the toy rockets is sold by the foot. If 8 feet cost $16.89, what is the cost for 30 feet of pipe sold at the same unit rate?

• A. $2.11

• B. $4.50

• C. $63.34

• D. $506.70