Constant Rate

Examples, videos, and solutions to help Grade 8 students learn how to define constant rate in varied contexts as expressed using two variables where one is t representing a time interval.

New York State Common Core Math Grade 8, Module 4, Lesson 11

Worksheets for Grade 8

Lesson 11 Student Outcomes

• Students know the definition of constant rate in varied contexts as expressed using two variables where one is t representing a time interval.
• Students graph points on a coordinate plane related to constant rate problems.

Lesson 11 Summary

• When constant rate is stated for a given problem, then you can express the situation as a two variable equation. The equation can be used to complete a table of values that can then be graphed on a coordinate plane.

NYS Math Module 4 Grade 8 Lesson 11 Examples & Exercises

Example 1
Pauline mows a lawn at a constant rate. Suppose she mows a 35 square foot lawn in 2.5 minutes. What area, in square feet, can she mow in 10 minutes? t minutes?

Example 2
Water flows at a constant rate out of a faucet. Suppose the volume of water that comes out in three minutes is 10.5 gallons. How many gallons of water comes out of the faucet in t minutes?

Exercises 1–3

1. Juan types at a constant rate. He can type a full page of text in 3 1/2 minutes. We want to know how many pages, p, Juan can type after t minutes.
   a. Write the linear equation in two variables that represents the number of pages Juan types in any given time interval.
   b. Complete the table below. Use a calculator and round answers to the tenths place.
   c. Graph the data on a coordinate plane.
   d. About how long would it take Juan to type a 5-page paper? Explain.
2. Emily paints at a constant rate. She can paint 32 square feet in five minutes. What area, A, can she paint in t minutes?
   a. Write the linear equation in two variables that represents the number of square feet Emily can paint in any given time interval.
   b. Complete the table below. Use a calculator and round answers to the tenths place.
   c. Graph the data on a coordinate plane.
   d. About how many square feet can Emily paint in 2 1/2 minutes? Explain.
3. Joseph walks at a constant speed. He walked to the store, one-half mile away, in minutes. How many miles, m, can he walk in t minutes?
   a. Write the linear equation in two variables that represents the number of miles Joseph can walk in any given time interval, t.
   b. Complete the table below. Use a calculator and round answers to the tenths place. c. Graph the data on a coordinate plane.
   d. Joseph’s friend lives miles away from him. About how long would it take Joseph to walk to his friend’s house? Explain.

• Show Step-by-step Solutions

Try the free Mathway calculator and problem solver below to practice various math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations.

We welcome your feedback, comments and questions about this site or page. Please submit your feedback or enquiries via our Feedback page.