Answer:
7.22?
Step-by-step explanation:
I don't think this site is gonna be a good help for you.
Answer: ![1\frac{7}{8}\ hours](https://tex.z-dn.net/?f=1%5Cfrac%7B7%7D%7B8%7D%5C%20hours)
Step-by-step explanation:
If they are working alone
Jim does of the job in 1 hour=
of work
John does of the job in 1 hour=
of work
Let x be the number of hours to do the job if they work together.
Thus, each hour, they do
of the job when they work together.
According to the question,
![\frac{1}{x}=\frac{1}{3}+\frac{1}{5}](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7Bx%7D%3D%5Cfrac%7B1%7D%7B3%7D%2B%5Cfrac%7B1%7D%7B5%7D)
![\Rightarrow\frac{1}{x}=\frac{5+3}{15}\\\Rightarrow\frac{1}{x}=\frac{8}{15}\\\Rightarrow\ x=\frac{15}{8}=1\frac{7}{8}\ hours](https://tex.z-dn.net/?f=%5CRightarrow%5Cfrac%7B1%7D%7Bx%7D%3D%5Cfrac%7B5%2B3%7D%7B15%7D%5C%5C%5CRightarrow%5Cfrac%7B1%7D%7Bx%7D%3D%5Cfrac%7B8%7D%7B15%7D%5C%5C%5CRightarrow%5C%20x%3D%5Cfrac%7B15%7D%7B8%7D%3D1%5Cfrac%7B7%7D%7B8%7D%5C%20hours)
∴ The number of hours to do the job if they work together= ![1\frac{7}{8}\ hours](https://tex.z-dn.net/?f=1%5Cfrac%7B7%7D%7B8%7D%5C%20hours)