Company C has a machine that, working alone at its constant rate

Company C has a machine that, working alone at its constant rate, processes 100 units of a certain product in 5 hours. If Company C plans to buy a new machine that will process this product at a constant rate and if the two machines, working together at their respective constant rates, are to process 100 units of this product in 2 hours, what should be the constant rate, in units per hour, of the new machine?

A. 50
B. 45
C. 30
D. 25
E. 20

Let new machine produces ‘X’ Units in 1 hr.

In 1 hr A produces – 20 U

Together it produces 50 U in 1 hr.

Now 20 + X = 50

X = 30

Ans C