Rate of Work:
Solve each rate of work problem. Remember, distance = speed x time. In the context of the rate of work problems,
quantity = rate x time.
Problem 1:
It takes 1.5 hours for Libby to mow the lawn. Anna can mow the same lawn in 2 hours. If Libby and Anna work together
how long to the nearest minute will it take to mow the lawn?
[52 minutes]
Problem 2:
Joey and Cosmo have a company building sheds. It takes Cosmo 6 days to build a shed. If they built it together, it would
take them 4 days. How long would it take to build the shed if Joey worked alone?
[J:12 d and C: 6 d]
Problem 3:
Doug takes twice as long as Becky to complete a project. Together they can complete the project in 10 hours. How long
will it take each of them to complete the project alone?
[D: 15 h, B: 30 h]
Problem 4:
A swimming pool can be filled by pipe A in 3 hours and by pipe B in 6 hours, if each pump is working on its own. It is
decided to fill the pool using both pipes. At 9 am pump A is started. At what time will the swimming pool be filled if
pump B is started at 10 am?
[11:20 am]
Problem 5:
A kitchen sink can be filled by the tap in 5 minutes, but it takes 7 minutes to drain a full sink. If both the tap and the drain
are open, how long will it take to fill the sink?
[17.5 min]
Problem 5:
A tank can be filled by pipe A in 5 hours and by pipe B in 8 hours, each pump working on its own. When the tank is full
and a drainage hole is open, the water is drained in 20 hours. If initially the tank was empty and someone started the two
pumps together but left the drainage hole open, how long does it take for the tank to be filled to the nearest minute?
[3 h 39 min]