What was your question that was never answered?
In order to make 119$ he would need to work 7 hours
1/2 in. = 5 ft
so., 1 in. = 5 * 2 = 10 ft
Now, 2 in = 10 * 2 = 20 ft
In short, Your Answer would be Option D
Hope this helps!

Now, If the exponent was negative like you asked....
Let f and s be the ages of the father and the son. We have

From the first equation we derive

Substitute this expression for f in the second equation and we have

The solutions to this equation are s=5 or s=37
Since the sum of the ages must be 42, the solutions would imply

We can only accept the first solution, since the second would imply a son older than his father!