Answer:
7,000 panels
Step-by-step explanation:
Let the number of panel produced by plant B be x , this means plant A produced 2x. This is because what they produced is twice as much.
Now, we know 5% and 4% of the panels produced were defective and the total number of defectives is 980. This means that:
[5/100 * 2x] + [4/100 * x ] = 980
(0.05 * 2x) +(0.04x ) = 980
0.1x + 0.04x = 980
0.14x = 980
x = 980/0.14 = 7,000 panels.