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 156331: 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?
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
Steven mixes drinks at the rate of 4 drinks per min
Sue mixes drinks at the rate of 2 drinks per min
Jack mixes drinks at the rate of 20/15= 4/3 drinks per min
Together they mix at the rate of 4+2+4/3= 7 1/3 drinks per min
So, our equation to solve is:
(7 1/3)x=20 or
(22/3)x=20 multiply each side by 3
22x=60
x=2.73 min----------------------ans
CK
Steven=4*2.73=10.91 drinks
Sue=2*2.73=5.45 drinks
Jack=(4/3)*2.73=3.64 drinks
10.91+5.45+3.63=~~~~20 drinks
Hope this helps--ptaylor