Answer :
Answer:[tex]\frac{10}{3}[/tex]
Step-by-step explanation:
Given
Bob can Paint a fence in 5 hr
so full job can be done in 5 hr
in 1 hr [tex]\frac{1}{5}[/tex] job is done
suppose Jen done the work in x hr
so in 1 hr [tex]\frac{1}{x}[/tex] part of job is done
Also if they combine they can do the job in 2 hr
so in 1 hr [tex]\frac{1}{2}[/tex]
so [tex]\frac{1}{5}+\frac{1}{x}=\frac{1}{2}[/tex]
[tex]\frac{1}{x}=\frac{1}{2}-\frac{1}{5}[/tex]
[tex]\frac{1}{x}=\frac{5-2}{10}[/tex]
[tex]x=\frac{10}{3} hr[/tex]