Question 427814
I have a question that says if Jack can mix 20 drinks in 5 minutes,
 Lisa can mix 20 drinks in 10 minutes, and Jorge can mix 20 drinks in 15 minutes,
 How long will it take all three of them to mix 20 drinks.
:
Here is a simple equation you can use to solve this
Let t = time required working all together
Let the completed job = 1 (the mixing of 20 drinks)
{{{t/5}}} + {{{t/10}}} + {{{t/15}}} = 1
You can clear the denominators by multiplying by 30, and solve for t