Question

To shop a package, a company charges a one-time fee plus a fee based on the weight of the package. The table below shows the total shipping costs for four packages of different weights.

Answer 1

C = $5 + $1.5(w)

Explanation:

Given the following information :

Total shipping cost :

One time fee + fee based on package weight

Given the table :

Weight in pounds - - - - Total shipping cost($)

___4__________________11

___8__________________17

___12_________________23

___16_________________29

We can deduce from the table

For a package that weighs (w) 4 pounds

Total shipping cost = $11

Let one time fee = f

Fee based on weight = r

f + 4(r) = 11 - - - - - (1)

For a package that weighs (w) 8 pounds

Total shipping cost = $17

One time fee = f

Fee based on weight = r

f + 8r = 17 - - - - - (2)

From (1)

f = 11 - 4r - - - (3)

Substitute f = 11 - 4r in (2)

11 - 4r + 8r = 17

-4r + 8r = 17 - 11

4r = 6

r = 6/4

r = 1.5

Put r = 1.5 in (3)

f = 11 - 4(1.5)

f = 11 - 6

f = 5

Hence one time fee = $5

Charge based on weight = $1.5

Hence, Total shipping cost 'C' for a package weighing 'w' will be :

C = $5 + $1.5(w)