Question

The equation c= 0.25n can be used to find the cost (c) of buying n number of apples.

A) What is the constant of proportionality in this equation?
B) What information does the constant of proportionality provide us?
C) How many apples can you buy for $3?

Be sure to answer parts A, B and C. Make sure that you label each answer.

Answer 1

(a) The constant of proportionality is 0.25

(b) 1 apple = $0.25

(c) $3 = 12 apples

Explanation:

Given

`c= 0.25n`

Solving (a): The constant of proportionality;

For an equation:

`c=kn`

Where

k = constant of proportionality

By comparing:
`c=kn` to
`c= 0.25n`

`k = 0.25`

Hence, the constant of proportionality is 0.25

Solving (b): What information does
`k = 0.25` gives.

It represents the unit rate.

So, it means that 1 apple costs $0.25

Solving (c): Number of apples for $3.

This means that
`c = 3`

Substitute 3 for c in
`c= 0.25n`

`3 = 0.25n`

Make n the subject

`n = (3)/(0.25)`

`n = 12`