Yes they are proportionate
Equation for Kelli's earning = 20x + 100
Equation for Karl's earning = 25x + 50
Now, 20x +100 = 25x +50
25x-20x = 100-50
5x = 50
x = 10
So, your answer is 10 hours.
Hope this helps!
not letting me add answer
Refer to the attachment
