Solutions
- Anna and Carlos need to make the dinners. Bill and Dianne need to make the desserts.
- Anna and Carlos can each make 30 dinners in an hour.
30/180 + 30/180 = 1/t
1/6 + 1/6 = 1/t
t+t = 6
t = 3. It will take Anna and Carlos 3 hours to make all the dinners.
Bill can make 40 desserts in an hour. Dianne can make 60 desserts in an hour.
40/180 + 60/180 = 1/t
2t + 3t = 9
5t = 9
t = 1 4/5 hours. It will take Bill and Dianne 1 hour and 48 minutes to make all of the desserts. When they are done, they can help with the dinners.