Let x be the number of panels plant A produces and lat y be the number of panels plant B produces.
We knot that plant A produces 4 times as many panels as plant B, this means that:

We also know that 5% of panels produced by plant A are defective, this can be express as:

3% of panels produced by plant B are defective, this can be express as:

And we know that the sum of defective panels is equal to 2530, then we have:

Hence we have the system of equations:

To solve it we plug the value of x from the first equation into the second one and solve for y:

Since y is the number of panels plant B produced we conclude that plant B produced 11,000 panels.