Answer:
20 hours
Step-by-step explanation:
Computer download=5 hours
Computer + Extra processor=4 hours
Computer's rate =1/5 per hour
Computer + extra processor rate=1/4 per hour
Extras processor rate=1/x
Where,
x=how long it takes extra processor to get the job done on its own.
To find x, we have to solve the equation
1/5 + 1/x = 1/4
Subtract 1/5 from both sides
1/5 + 1/x -1/5 = 1/4-1/5
1/x=1/4-1/5
1/x = 5-4/20
1/x = 1/20
Cross product
1(20)=x(1)
20=x
x=20 hours
It would have taken the new extra processor alone 20 hours to download the movie
