Answer:
Plant B produced 17000 panels.
Step-by-step explanation:
Two factory plants are making TV panels.
Yesterday, Plant A produced 3000 fewer panels than Plant B did.
Five 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 1380 defective panels?
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A = B - 3000 (1) ("Plant A produced 3000 fewer panels than Plant B did")
0.05A + 0.04*B = 1380. (2) (counting defective panels)
Substitute expression (1) into eq(2). You will get
0.05*(B-3000) + 0.04*B = 1380,
0.05*B - 150 + 0.04*B = 1380,
0.09*B = 1380 + 150 = 1530 ====> B = 1530%2F0.09 = 17000.