A company has 2 types of machines , type R and type S. Operating at a constant rate, a machine of type R does a certain job in 36 hours and type S does the same job in 18 hours.If the company used the same number of each type of machine to do the job in 2 hrs,how many type R machines were used?/
3
4
6
9
12
3
4
6
9
12
Maxx
