Convert rates and units in several steps

Grade 9 Math Worksheet - Building Confidence

Circle the best answer.

1. 1.

   A phone has 28 GB of data and uses 14 GB per week. Pia writes D for the GB left after d days. Which equation is right?

   • D = 28 - 14d
   • D = 28 - 98d
   • D = -2d
   • D = 28 - 2d
2. 2.

   A taxi charges $3 plus $1.80 per mile. Milo writes C for the cost of a ride of k kilometers (1 mile = 1.6 km). Which equation is right?

   • C = 3 + 2.88k
   • C = 3 + 1.8k
   • C = 1.125k
   • C = 3 + 1.125k
3. 3.

   A plant is 12 cm tall and grows 2.1 cm per day. Kira writes H for the height after w weeks. Which equation is right?

   • H = 12 + 14.7w
   • H = 14.7w
   • H = 12 + 2.1w
   • H = 12 + 0.3w
4. 4.

   Tala's car travels 30 miles per gallon, and gas costs $3.60 per gallon. Which expression gives the cost in dollars per mile?

   • 3.60 + 30
   • 3.60 ÷ 30
   • 30 ÷ 3.60
   • 3.60 × 30
5. 5.

   A hose delivers 1,500 liters per hour. Zee wants the liters per minute. Which expression gives it?

   • 1,500 + 60
   • 1,500 × 60
   • 1,500 ÷ 60
   • 60 ÷ 1,500
6. 6.

   Luz burns 420 calories per hour while walking 6 kilometers per hour. Which expression gives the calories per kilometer?

   • 420 ÷ 6
   • 420 × 6
   • 6 ÷ 420
   • 420 + 6
7. 7.

   The cost C in dollars of k kilowatt-hours is C = 0.08k + 5. Esme asks: what does 0.08 tell us?

   • Each extra dollar of cost uses 0.08 kilowatt-hours.
   • Each extra kilowatt-hour adds $0.08 to the cost.
   • The total cost for any amount of electricity is $0.08.
   • The cost is $0.08 when no electricity is used.
8. 8.

   The height H in cm of a plant after d days is H = 12 + 2.1d. Jun asks: what does 2.1 tell us?

   • The plant is 2.1 cm tall at every age.
   • Each centimeter of growth takes 2.1 days.
   • The plant is 2.1 cm tall at the start.
   • The plant grows 2.1 cm every day.
9. 9.

   A rider's distance D in km after t hours is D = 18t + 4. Noah asks: what does 18 tell us?

   • Each kilometer takes the rider 18 hours.
   • The rider starts 18 km from the start line.
   • The rider covers 18 km each hour.
   • The rider covers 18 km in total.
10. 10.

    A pool's volume V in liters after m minutes of draining is V = 900 - 45m. Ari asks: what does 45 tell us?

    • The pool loses 45 liters in total.
    • The pool loses 45 liters each minute.
    • The pool starts with 45 liters.
    • Each liter drained takes 45 minutes.