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.

DayM T W Th Fr
# of students 2 5 3 3 5
  1. How many hours would students have to work each week in order to finish the garden on time? I think it would be 15 hours. 3 x 5 = 15 x 3 wks = 45 hours.
  2. Will 3 students be working every day? I put no.
  3. This one I don't understand. On the second week of the project, the whole class is taking a field trip on Friday. How many students will have to work on a different day that week? Explain. My dad thinks 2. I thought 5. Which is it?
  4. The students worked for 12 hours a week during the first two weeks.
    • How many hours will they need to work in the third week in order to complete the garden on time? I put 21 hours. 45 hours - 24 hours = 21
    • How many hours should each student work in the final week in order to complete the garden on time? Explain. I put 15 into 21 and got 1 r. 6. Does that mean 1.6 hours or how else do you write it if that is correct.
  5. I just need to know the answers to #3 and #4. I didn't quite understand them.
    Thanks for your help. Adam

    Hi Adam,

    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.

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