Two factory plants are making TV panels. Yesterday, Plant A produced 2000 fewer panels than Plant B did. Two percent of the panels from Plant A and 4% of the panels from Plant B were defective. How many panels did Plant B produce, if the two plants together produced 500 defective panels?

Solution:

Plant B produce x panels

Plant B produce (x-2000) panels

So

2%*(x-2000)+4%*x=500

x = 9000

So Plant B produce 9000 panels