Question

please help!! i have a final tomorrow and i don't know how to solve these types of problems ):

Answer 1

Patrick can load moving boxes into the truck in 4 hours and Keith can load the truck in 5 hours. How long does it take them to do it together?

Answer 2

1/4 +1/5

Answer 3

5+4/20

Answer 4

9/20

Answer 5

So...9 hours and 20 minutes

Answer 6

If it takes Patrick 4 hrs to move, that means he can do 1/4 in an hour.

Same with Keith, he would be able to do 1/5 of the job per hour

Hint for these kind of problems, the time is just the recipricol or their individual time

Now add 1/4 and 1/5 to get their total work rate

Answer 7

@SanjanaP how did you get the 9?

Answer 8

And formula is

rate x time =work

And their work=1 because they are only moving/loading once
rate=whatever 1/5+1/4 is

Plug into equation and solve for time

(1/5 + 1/4) time = 1

Answer 9

Well see....fractions