Solving a percent mixture problem using liner equation

Question

two factory plants are making tv panels. yesterday plant A produced twice as many panels as plant B. five percent of the panels from plant A and 2% of the panels from plant B were defective. how many panels did Plant B produce, if the two plants together produced 1320 defective panels?

Answer 1

Let x be the number of panels produced by B.

Then the number of panels produced by A is 2x.

2% of x is 0.02x panels produced by B are defective.

5% of 2x is 0.1x panels produced by A are defective.

In total 0.12x panels are then defective.

Which means 0.12x = 1320 defective panels.

Solved for x ===> 11000 defective panels produced by B.