Question

Jackson can remove the shingles off of a house in 7 hours, while Martin can remove the shingles in 5 hours. How long will it take them to remove the shingles if they work together?

Answer 1

Answer:
`2\ hours\ and\ 55\ minutes`

Explanation:

WE can use the following formula:

`(T)/(A)+(T)/(B)=1`

Where "T" is the time time working together, "A" the time for person A working alon and "B" is the time for person B working alone.

Based on the data given in the exercise, we can identify that:

`A=7\\B=5`

Therefore, substituting these values into the formula and solving for "T", we get that this is:

`(T)/(7)+(T)/(5)=1\\\\(12T)/(35)=1\\\\T=(1)((35)/(12))\\\\T=2.9167\ hours`

Since 1 hour has 60 minutes:

`(0.9167h)((60min)/(1h))=55min`

Therefore, if they work together, it will take them 2 hours and 55 minutes to remove the shingles.