1. Section 2

1.19. Explore 2

Mathematics 20-3 Module 3

Section 2: Slope—Rate of Change

 

Try This 2

 

This is a photo of a person using a grass trimmer.

© Horticulture/2658120/Fotolia

 

Aron is working with a grass trimmer. She has to mix oil with gasoline in a 1:50 ratio. Aron needs to have at least 5 L of mixture to complete her day’s work. If she started with 5 L of gasoline, how much oil would Aron have to add?

  1. Set up a proportion to represent this question. You know the following:

    • The oil to gasoline ratio is 1:50.
    • There is 5 L of gasoline added.
    • The amount of oil is unknown; let it be x.

    answer

  2. Solve your proportion by rearranging or cross multiplying to find x. answer

course folder Save your responses to your course folder.

 

Self-Check 1
  1. The company Aron is working for has ten other workers using grass trimmers. The company decided to do the mixing in one large container. It is hoped there will be enough of the gas-oil mixture to last the workers a week. In making the mixture, 5.8 L of oil were used. How much gasoline was used? Answer

  2. This photo is of a collection of strawberry shortbread cookies.
    © Michael Felix/7291730/Fotolia
    Sam needs some cookies for a bake sale at school. Money is being raised for a nearby elementary school’s hot lunch program. He found this simple shortbread cookie recipe on the Internet. The problem is that the recipe makes only 8 cookies, and Sam needs 24 cookies. Use proportional reasoning to find the quantities of flour, sugar, and butter needed to make 24 cookies. Answer

     

    Shortbread Recipe

     

    • cup flour, sifted
    • cup superfine sugar
    • cup room temperature butter

 

Rearrange

 

Cross multiply

 



 

Aron would have to add 0.1 L (or 100 mL) of oil to the 5 L of gasoline.