Answer:
I think it is wrong because it is unlike term
defective : working = 1/15 ( x20 ) 20/300
so the answer is 20 light bulbs
12 hours worth $87
1 hour would be $87/12 = $7.25
9 hours worth $65.25
1 hour would be $65.25/9 = $7.25
The constant of proportionality is $7.25 per hour.
