I'm in fourth grade and here's the problem.
Robin's class is developing a community garden. There are 15 students in Robin's class. They volunteer to work in a community garden at various times during the school week. Robin's teacher says it will take about 3 weeks to complete the project if 3 students work 1 hour each day. Some students can work on more than one day. The following table lists the number of students who can work on various days.
I just need to know the answers to #3 and #4. I didn't quite understand them.
I'm not sure about 3 either. I think that the answer is probably 5 but your father could be right also. After reading part 4 and seeing that you can "catch up" in week 3 then I would say that even 0 is a valid answer to 3.
For part 4 I agree with your answer. As to how to write 1 r. 6 hours, I suggest that you express it in minutes rather than hours. 21 hours is 21*60 = 1260 minutes. 1260 divided by 15 is 84 minutes which is 60 minutes plus 24 minutes, that is 1 hour and 24 minutes.Cheers,