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 49 hrs and a machine of type S does the same job in 14 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?
Choose the correct choice
A) 49/9  B) 44/9  C) 46/9  D) 41/9  E) 43/9
Rate of machine R =1/49   Rate of machine S =1/14   since same no of machines used for R and S to do the same work in 2 hrs   So collective rate needed to finish the work in 2 hrs= 1/2   Let the no of machine be x   So, x/49 +x/14 =1/2   9x=49   x=49/9   So no of machine R is 49/9   49/9nswer 49/9
<result>A</result>
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 49 hrs and a machine of type S does the same job in 14 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?