- Four machines, working independently at the same constant rate, can
fill a production lot in 3 hours. How many of these machines would be
needed to fill the lot in 30 minutes?
A 12
B 24
C 36
D 40
E 48 - Working at a constant rate, a cook can create a batch of pasta in 20
minutes. Another cook, working at a constant rate, can create the
same batch of pasta in 10 minutes. If the two cooks work together but
independently, how many hours will it take them to create 3 batches
of pasta?
A (^14)
B (^13)
C (^12)
D (^35)
E 2
- A hose fills an empty tank with water at a rate of 15 liters/second. At the
same time, water drains from the tank at a rate of 10 liters/second. If the
tank has a capacity of 200 liters, in how many seconds will the tank be
half full?
A 4
B 8
C 20
D 25
E 40 - Working together at their respective constant rates, Bob and Sam can
mow a lawn in 12 hours. If Bob’s rate is twice Sam’s rate, how many hours
would it take Bob, working alone, to mow the lawn?
A 15
B 18
C 24
D 32
E 36
CHAPTER 12 ■ FROM WORDS TO ALGEBRA 34704-GRE-Test-2018_313-462.indd 347 12/05/17 12:04 pm