A company has two types of machines, type R and type S.
A company has two types of machines, type R and type S. Operating at a constant rate, a machine of type R does a certain job in 24 hrs and a machine of type S does the same job in 12 hours. If the company used the same number of each type of machine to do the job in 2 hours, how many machines of type R were used?
Answer/Solution
4
Steps/Work
Rate of machine R = 1/24
Rate of machine S = 1/12
Rate of R+S = 1/8
To finish the work in 2 hrs, the combined rate needs to be 1/2.
x * 1/8 = 1/2
x = 4
The answer is B.
Rate of machine S = 1/12
Rate of R+S = 1/8
To finish the work in 2 hrs, the combined rate needs to be 1/2.
x * 1/8 = 1/2
x = 4
The answer is B.