1. ## Problem involving work

I think I figured it out but here is the problem
One person can do a task in 10hrs, a second can do it in 15 and the third can do it in 20. Together how long will it tak
so here is what I came up with
x/10+x/15+x/20=1
60(x/10+x/15+x/20)=1*60
6x+4x+3x=60
13x=60
13x/13=60/13
x=4.62

2. It's right.

3. Hello, roachbeats!

I think I figured it out

One person can do a task in 10 hrs, a second in 15 hours, and a third in 20 hours.
Together, how long will it take?

So here is what I came up with: . $\frac{x}{10}+\frac{x}{15}+\frac{x}{20} \:=\:1$

. . $60\left(\frac{x}{10}+\frac{x}{15}+\frac{x}{20}\rig ht)\:=\:1\cdot60$

. . $6x+4x+3x\:=\:60 \quad\Rightarrow\quad 13x\:=\:60 \quad\Rightarrow\quad x\:=\:\frac{60}{13} \:\approx\:4.62\text{ hrs}$

Absolutely correct! . . . Lovely work!