Question

If Jim Roller can paint a room in 3 hours while John Brush would take 5 hours, how long will they take if they work together? 1/8 hour

Answer 1

Your answer is 1 7/8. Hope this helps!

Answer 2

Answer: $1\frac{7}{8}\ hours$

Step-by-step explanation:

If they are working alone

Jim does of the job in 1 hour=$\frac{1}{3}$ of work

John does of the job in 1 hour=$\frac{1}{5}$ of work

Let x be the number of hours to do the job if they work together.

Thus, each hour, they do $\frac{1}{x}$ of the job when they work together.

According to the question,

$\frac{1}{x}=\frac{1}{3}+\frac{1}{5}$

 $\Rightarrow\frac{1}{x}=\frac{5+3}{15}\\\Rightarrow\frac{1}{x}=\frac{8}{15}\\\Rightarrow\ x=\frac{15}{8}=1\frac{7}{8}\ hours$

∴ The number of hours to do the job if they work together= $1\frac{7}{8}\ hours$