Question 991515
They will never make the same amount unless Bill tutors 1 and 1/3 more hours than Sam. After that they make the same regardless of hours (they charge the same per hour. Otherwise, we could re-write the problem as "Sam charges what Bill charges + 20. When will they make the same?" And we can easily see that they will never make the same amount, because Sam always charges 20 more and they make the same per hour otherwise.