Math 9 Graphing and Interpreting Relations Lesson 2-2
Name ______
1. a) How much does a pizza with 6 toppings cost?
b) A pizza costs $7.50. How many toppings does it have?
c) Warren orders a pizza with mushrooms, bacon, onions, and green peppers. What is the cost of his pizza?
d) What is the cost of a pizza that contains your favourite toppings?
2. a) What is the average height of girls at this age?
i) 10 years ii) 7 years iii) 16 years
b) What is the age of boys with this average height?
i) 110 cm ii) 134 cm iii) 170 cm
c) At what ages do boys and girls have the same average height?
3. a) Graph the relation between the number of kilometres Brad covered on a trip and the number of hours of the trip. Is it reasonable to join the points? Explain.
Elapsed Time (h) / 1 / 2 / 3 / 4 / 5 / 6 / 7Distance (km) / 100 / 200 / 300 / 400 / 500 / 600 / 700
b) About how long did it take to travel 150 km? 375 km? 425 km?
c) What distance was travelled in 30 minutes? 4.5 hours? 5.25 hours?
d) In which time interval did Brad stop to rest?
4. A cab company charges a base fee of $1.70 and then $0.75/km or part thereafter.
a) Show the relation between kilometres driven and charges in a graph for up to 9 km.
b) What is the charge for a 7.5 km ride?
c) How far can you travel for $7.00?
5. The cost, C, in cents, of making n photocopies is given by the formula: C = 70 + 6n.
a) Make a table of values showing the cost of up to 100 copies
b) Draw the graph of the relation.
c) Use the graph to estimate the cost of 75 copies.
d) Use the graph to estimate how many copies can be made for $3.50.
MOM (Atlantic) Page 117 – 118
6. Turkeys are cooked at an oven temperature of 165oC. For turkeys between 3 kg and 8 kg, the cooking time is 30 minutes per kilogram. The time, t hours, is related to the mass, k kilograms, by this equation: t =
a) Copy and complete this table.
k (kg) / 3 / 4 / 5 / 6 / 7 / 8t (h)
b) Graph t against k.
c) Does it make sense to join the points? Explain why.
d) For each kg, how much does the time increase?
e) Turkeys larger than 8 kg need less cooking time per kilogram. How would the graph change for these turkeys?
f) Turkeys with stuffing need more cooking time per kilogram. How would the graph change for stuffed turkeys?
7. The yearbook club is choosing a company to print the school yearbook. Blue Heron Yearbooks charges $8000 for set-up and $4 per copy. The equation that represents this relation is C = 8000 + 4n, where C is the cost in dollars and n is the number of books printed. Miles Ahead Yearbooks charges $8400 for set-up and $3 per copy. The equation that represents this relation is C = 8400 + 3n. Which company charges less? Explain.
PAGE 118
10. The trip to the cross-country running provincial finals in St. John’s costs $1940 for the bus and $80 per runner for meals and accommodation. The cost, C dollars, is modelled by the equation C = 1940 + 80n, where n represents the number of runners.
a) Copy and complete this table
n / 0 / 10 / 20 / 30 / 40 / 50C ($)
b) Graph the relation
c) Does it make sense to join the points? Explain why.
d) At what value does the line cross the C axis? What does this value represent?
e) As the number of runner increases by 1, how much does the cost increase?
f) Use the graph to estimate the cost for each number of runners.
i) 25 ii) 12 iii) 48
g) Suppose the runners stay with local families so the cost per runner is reduced to $32. How would the graph and equation change?
h) Suppose the cost of the bus is covered by fundraising. So, the only expense is $80 per runner. How would the graph and equation change?