First you add 3 and 2 so that is 5 and then you subtract 5 from 9 so the answer is 4.
If it takes eight men ten hours, it would take seven men nine hours, six men eight hours, five men seven hours and that brings us to the answer you need. It would take four men six hours.
Well the line is called a ray because because the left of the endpoint is a dot and it doesn't go anywhere. So your answer is a ray.
hope that helped
