Working simultaneously at their respective constant rates, Machines A and B produce 800 nails in x hours. Working alone at its constant rate, Machine A produces 800 nails in y hours. In terms of x and y, how many hours does it take Machine B, working alone at its constant rate, to produce 800 nails?
The above sol is awesome.... but i did it the longer way, algebraically...
rate of A be a and B be b
a + b = 800/x
a = 800/y
Use 2 in 1... we get
b = 800 (y-x) / xy
Rate of B * time = Work done by B (we want time)800 (y-x) / xy * t = 800
t = xy / (y-x)