Question

PLEASE HELP ASAP! IT'S EASY WORD PROBLEM!!!!!!!! My computer can download a movie in 5 hours. If I install an extra processor it can download the movie in 4 hours. How long, working alone, would it have taken the new extra processor to download the movie?

Answer 1

t = 2,22 h

Explanation:

At the beginning with the first processor, we download in 5 hours the whole movie, then in 1 hour, that processor downloads 1/5 of the movie.

If with the two processors we download the movie in 4 hours in 1 hour we download 1/4 of the movie.

In 1 hour with the two processors, we get 1/4, and in 1 hour with the old processor we get 1/5

Then in 1-hour the old processor plus contribution of the new one will download 1/4 of the movie or

1/5 + x = 1/4

x = 1/4 - 1/5

x(h) = 5 + 4 /20 x = 9/20 or 0,45 of the movie in 1 hour

Working along the new processor will do 0,45 ( 9/20) in 1 hour, to finish the whole movie it will need to download 11/20

If in 1 hour download 9/20

x 11/20

x(r) = (11/20) / (9/20) = 11/9 x(r) = 1,22 (h)

Then total time for the new processor to download the movie is:

t = 1,22 + 1

t = 2,22 h