While working alone at their respective constant rates, computer X processes 240 files in 4 hours and computer Y processes 240 files in 8 hours. If all files processed by these computers are the same size, how long would it take the two computers, working at the same time and at their respective constant rates, to process a total of 240 files?

8/3 hours

Explanation:

For this question, let us say that 1 job contains 240 files

Computer X does this job in 4 hours

Computer Y does the same job in 8 hours

All we need to find is how long it will take both computers to finish the job

Now we apply the basic combined work formula, which is

Combined Time = (time a * time b)/(time a + time b)

And we known that time a = 4 hrs,

We then substitute this values into the equation to get

Combined time = (4*8)/(4+8)

= 32/12

= 8/3 hours

the formula for work is

f*d

therefore work=2.0n*3.0=6n*m