Question

Two factory plants are making TV panels. Yesterday, Plant A produced 3 times as many panels as Plant B. Three percent of the panels from Plant A and 4% of the panels from Plant B were defective. How many panels did Plant A produce, if the two plants together produced 1300 defective panels?

Answer 1

Let us assume the number of panels produced by Plant A = z
Let us assume the number of panels produced by Plant B = y
Then
x = 3y
0.03x + 0.04y = 1300
Multiplying both sides of the second equation by 100, we get
3x + 4y = 130000
Putting the value of x from the first equation in the second equation, we get
3x + 4y = 130000
3(3y) + 4y = 130000
13y = 130000
y = 10000
Then
x = 3 * 10000
   = 30000
From the above deduction, we can conclude that the number of panels made by Plant A is 30000.