The factory plants are making TV panels. Yesterday, Plant A produced 2000 fewer panels than Plant B did. Four 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 820 defective panels? Number of panels produced by Plant B: $\square$ $\times \quad 5$

Step 1 ：Let's denote the number of panels produced by Plant B as x. Then the number of panels produced by Plant A is x - 2000.

Step 2 ：According to the problem, 4% of the panels from Plant A and 2% of the panels from Plant B were defective. So, the total number of defective panels is 0.04 * (x - 2000) + 0.02 * x.

Step 3 ：We know that this total is 820. So, we can set up the equation 0.04 * (x - 2000) + 0.02 * x = 820 and solve for x.

Step 4 ：The solution to the equation is x = 15000. This means that Plant B produced 15000 panels.

Step 5 ：Final Answer: The number of panels produced by Plant B is \(\boxed{15000}\).