Given:
The cost of a black printer ink cartridge is $16.99.
The cost of a colour printer ink cartridge is $21.99.
A total of 47 of these cartridges were sold for a total of $908.53.
To find:
The number of items sold in each type.
Step-by-step explanation:
Let x be the number of a black printer ink cartridge.
Let y be the number of a colour printer ink cartridge.
According to the question,
![\begin{gathered} x+y=47.............(1) \\ 16.99x+21.99y=908.53.............(2) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/6q07llkzcqbm0tav8hwg5manis6ja7fbo1.png)
Multiplying 16.99 in equation (1), we get
![16.99x+16.99y=798.53...........(3)](https://img.qammunity.org/2023/formulas/mathematics/college/e3cibnhtnsy7vsby9ogmtle3z65wtarihw.png)
Subtract (3) from (2), we get
![\begin{gathered} 5y=110 \\ y=22 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/a7hyxbtdco8fp0ind8xndsvxx8dv59mn8i.png)
Substitute in equation (1) we get,
![\begin{gathered} x+22=47 \\ x=47-22 \\ x=25 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/m9y1p7cettjtrvflgjwwdz0aqdzk9xzif4.png)
Thus,
The number of a black printer ink cartridge is 25.
The number of a colour printer ink cartridge is 22.
Final answer:
• The number of a black printer ink cartridge is 25.
,
• The number of a colour printer ink cartridge is 22.