Question

An office supply store recently sold a black printer ink cartridge for $14.99 and a color printer ink cartridge for $23.99. At the start of a recent fall semester, a total of 63 of these cartridges was sold for a total of $1133.37How many of each type were purchased?

Answer 1

Let x be the number of black ink cartridges sold, and y the number of color ink sold, therefore, with the given information we can set the following system of equations:

`\begin{gathered} 14.99x+23.99y=1133.37, \\ x+y=63. \end{gathered}`

Solving the second equation for x, we get:

`x=63-y.`

Substituting the above result in the first equation of the system, we get:

`14.99(63-y)+23.99y=1133.37.`

Solving for y, we get:

`\begin{gathered} 14.99*63-14.99y+23.99y=1133.37, \\ 9y=1133.37-944.37=189, \\ y=21. \end{gathered}`

Substituting y=21 in the second equation of the system, we get:

`x+21=63.`

Solving for x, we get:

`x=63-21=42.`

Answer:

42 black printer ink cartridges were sold, and 21 of the other type.