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?

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.

6/ 11 = 0.545454 so your answer is55%