20. Reggie can paint a house in 5 hours. Fernando can paint the same house in 6 hours while Mark can do the same job in 3 hours. First, Reggie and Fernando start working together for 2 hours. Then Mark

finished the job alone. How long did it take mark to finish?

rate

time

Total work done

Reggie

Fernando

Mark

24. In a river that flows at 4km/h, a boat takes twice as long to travel 40km upstream as it does to travel

32km downstream At what rate does the boat travel in still water?

Rate

Distance

Time

upstream

downstream