Section 5-4B Notes: Creating Function Rules from Word Problems
Ex. 1 A coffee shop buys a certain coffee blend by the pound. Each pound of the blend costs $1.19. Write a
function rule to describe this relationship. How much would 12 lbs of this blend costs?
Define the variable(s):
Create a table:
Create the function rule:
12 lbs of Blend:
Ex. 2 Suppose you borrow money to buy a lawn mower that costs $245. You charge $18 for each lawn you
mow. Write a rule to describe your profit as a function of the number of lawns you mow.
Define the variable(s):
Create a table:
Create the functions rule:
How much would you make if you mowed 5 lawns?
How many lawns would you have to mow to start making a profit?
Ex. 3 An internet job requires that you pay an investment fee of $125. Once you have paid that fee, you will
make $15 for each plopjopper that you sell. Create a rule that describes your profit.
If you sold 7 plopjoppers how much money will you have made?
If you made a profit of $10, how many plopjoppers did you sell?
Ex. 4 The cost of renting a snow blower is $13.50 per hour. (1)Write a rule and then (2) tell what the cost of
renting the snow blower for 6 hours would be. (3) If you had $200 to rent a snow blower, how many hours
could you rent one?