Lesson 3
Revisiting Proportional Relationships
Let’s use constants of proportionality to solve more problems.
Problem 1
It takes an ant farm 3 days to consume \(\frac12\) of an apple. At that rate, in how many days will the ant farm consume 3 apples?
Problem 2
To make a shade of paint called jasper green, mix 4 quarts of green paint with \(\frac23\) cups of black paint. How much green paint should be mixed with 4 cups of black paint to make jasper green?
Problem 3
An airplane is flying from New York City to Los Angeles. The distance it travels in miles, \(d\), is related to the time in seconds, \(t\), by the equation \(d=0.15t\).
 How fast is it flying? Be sure to include the units.
 How far will it travel in 30 seconds?
 How long will it take to go 12.75 miles?
Problem 4
A grocer can buy strawberries for $1.38 per pound.
 Write an equation relating \(c\), the cost, and \(p\), the pounds of strawberries.
 A strawberry order cost $241.50. How many pounds did the grocer order?
Problem 5
Crater Lake in Oregon is shaped like a circle with a diameter of about 5.5 miles.

How far is it around the perimeter of Crater Lake?

What is the area of the surface of Crater Lake?
Problem 6
A 50centimeter piece of wire is bent into a circle. What is the area of this circle?
Problem 7
Suppose Quadrilaterals A and B are both squares. Are A and B necessarily scaled copies of one another? Explain.