SOLUTION: If Steven can mix 20 drinks in 5 minutes, Sue can mix 20 drinks in 10 minutes, and Jack can mix 20 drinks in 15 minutes, how much time will it take all 3 of them working together t

Algebra ->  Rate-of-work-word-problems -> SOLUTION: If Steven can mix 20 drinks in 5 minutes, Sue can mix 20 drinks in 10 minutes, and Jack can mix 20 drinks in 15 minutes, how much time will it take all 3 of them working together t      Log On


   

Question 262966: If Steven can mix 20 drinks in 5 minutes, Sue can mix 20 drinks in 10 minutes, and Jack can mix 20 drinks in 15 minutes, how much time will it take all 3 of them working together to mix the 20 drinks?
A. 2 minutes and 44 seconds
B. 2 minutes and 58 seconds
C. 3 minutes and 10 seconds
D. 3 minutes and 26 seconds
E. 4 minutes and 15 seconds

Found 2 solutions by ptaylor, richwmiller:
Answer by ptaylor(2198) About Me  (Show Source):
You can put this solution on YOUR website!

Let x=amount of time it takes all three, working together, to mix 20 drinks
Steve mixes at the rate of 4 drinks per min
Sue mixes at the rate of 2 drinks per min
Jack mixes at the rate of (4/3) drinks per min
Together, they mix at the rate of 4+2+(4/3) drinks per min=7 1/3=22/3 drinks per min
So, our equation to solve is:
(22/3)*x=20 multiply each side by 3
22x=60
x=2.73 min
CK
(2.73)*(7.33)=20
20.01~~~~20
Hope this helps---ptaylor

Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
2.73*60=163.8 minutes
163.8-120=43.8~44 minutes
so 2 hr 44 minutes