Page 6 - Mathematics Literacy Grade 11

Unit 1: Constant/ fixed relationship

There are many situations in which there is a fixed or constant relationship between
the terms in a relationship, such as renting a room, paying your bond and paying
your television subscription. In these situations, there is a fixed monthly payment.
Also hiring a car at a fixed rate per day, regardless of the kilometers travelled, may
be classified as a constant/fixed relationship.

Example 1

A school is taking 40 learners to the airport. The bus costs R3 200 per day and holds
40 learners. What will it cost the school to transport 35 learners in one day, 25
learners in one day and 39 learners in one day to the O.R. Tambo International
Airport which is about 115 kilometres from the school?

Number of people 1 10 25 35 39
Cost of the Bus R3200 R3200 R3200 R3200 R3200

As you can see from the table, as long as the number of learners is less
than 40, then the cost is constant. If we drew this relationship on a graph it
would look like:

R3 500
R3 000
Cost of the trip R2 000
R2 500

R1 500
R1 000
R500
R0
0 10 20 30 40 50
Number of people

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