Solving a percent mixture problem using a system of linear equations

Question

Two factory plants are making TV panels. Yesterday, Plant A produced
2000
fewer panels than Plant B did. Four percent of the panels from Plant A and
3%
of the panels from Plant B were defective. How many panels did Plant A produce, if the two plants together produced
620
defective panels?

 

Answer 1

The second sentence can be turned into an equation. If you assign plant A to be a and plant B to be b, then the second equation will look like

(0.04)a + (0.03)b= amount of defective planels