SOLUTION: Hank can wash and wax the car in 2 hours, Sally can do it in 1 hour, 30 minutes, and Hank, Sally, and Lena can do it in 40 minutes working together. How long would it take Lena,

Question 923126: Hank can wash and wax the car in 2 hours, Sally can do it in 1 hour, 30 minutes, and Hank, Sally, and Lena can
do it in 40 minutes working together. How long would it take Lena, working alone, to wash and wax the car?
Answer by srinivas.g(540) (Show Source): You can put this solution on YOUR website!
Hank can wash and wax the car in 2 hours
so in 1 hr , he can do 1/2 of the work
Sally can do it in 1 hour, 30 minutes (1.e 1.5 hr)
so in 1 hr he can do 1/1.5 of the work
three persons together can do it in 40 min ( 40 min = 40/60 = 2/3 hr)
three persons together can complete in 2/3 hr
In 1 hr they can do work
= work
I hr, lena alone can do = of the work
= of the work
= of the work
multiply and divide with 6 to each term
= of the work
= of the work
= of the work
= of the work
= of the work
so , 1 Hr Lena can do 1/3 of the work
so to complete full work , lena can take 3 hrs
so result is 3 hrs

RELATED QUESTIONS
if so can wash and wax a car in one hour and half can do the same job in 8 hours how long (answered by richwmiller,Vladdroid)

John can wash and wax a car in 4 hours. Max can wash and wax a car in 5 hours. How long... (answered by stanbon)

solve john can wash and wax his car in 6 hours on his own. if his little brother helps... (answered by fractalier)

jason can wash and wax his car in 4 hours. His younger sister can wash and wax the same... (answered by god2012)

Derek can wash and was a car in exactly 2 hours. Allison can do the same job in exactly 5 (answered by LinnW)

At the 4-H club fundraiser to wash and wax cars, Olivia can wash and wax a car in 4... (answered by ikleyn)

sally can drive 750 mile in 12 hours and 30 minutes. what is her unit rate in miles per... (answered by Alan3354,Helenpan2017@,josmiceli)

Janet can wax her car in 8 hours. When she works together with Darlene, they can wax the... (answered by josmiceli)