One pipe can fill a pool in 9 hours. Another pipe can fill the pool in 6 hours. How long would it take them to fill the pool if they were working together?
help asap please
One pipe can fill a pool in 9 hours. Another pipe can fill the pool in 6 hours. How long would it take them to fill the pool if they were working together?
help asap please
3.6 hours
Step-by-step explanation:
Let X be the total job
Combined speed = X/9 + X/6
LCM = 18
(2X + 3X)/18
5X/18 = X/T
T = 18/5
T = 3.6
The 2 pipes together take 2.7 hr, or 2 hrs and 42 min
to fill 3/4 of the pool
Step-by-step explanation:
3.6 hours
Step-by-step explanation:
To determine the time needed if they are working together, we use the formula
1/Ta + 1/Tb = 1 Tc
where Ta is the the time for the first item working alone
Tb is the time for the second item alone
Tc is the time for them working together
1/9 + 1/6 = 1/Tc
I multiply by 54Tc to clear the fractions
54Tc (1/9 + 1/6) = 1/Tc *54Tc
6Tc + 9 Tc = 54
Combine like terms
15Tc = 54
Divide each side by 15
15 Tc /15 = 54/15
Tc =3.6 hours
Answer= 4 hours.
The first pipe can fill one pool in nine hours. So in one hour, it can fill 1/9th of the pool. Same with the other pipe, it can fill 1/6th of the pool in other hour.
So 1/9 + 1/6 would represent the first hour of filling the pool. Since 1/9 + 1/6 = .277.. , 27% of the pool is filled. Repeat this until you get to 100% (full pool).
First hour, 1/6 + 1/9 = .27
Second hour, 2/6 + 2/9 = .5
Third hour, 3/6 + 3/9 = .83
Fourth hour, 4/6 + 4/9 = 1.11
So in 4 hours, the pool will be filled.