At 9:00 am, an empty water tank begins to be filled with water flowing through a hose at a rate of five gallons per minute. Seven hours later, water flowing through a second hose also starts to fill the tank at a rate of eight gallons per minute. Some time later, the first hose is turned off but the second hose continues to be used to fill the tank. At midnight the 7740-gallon tank is finally full. At what time was the first hose turned off?
At 9:00 am, an empty water tank begins to be filled with water flowing through a hose at a rate of five gallons per minute. Seven hours later, water flowing through a second hose also starts to fill the tank at a rate of eight gallons per minute. Some time later, the first hose is turned off but the second hose continues to be used to fill the tank. At midnight the 7740-gallon tank is finally full. At what time was the first hose turned off?
The second hose was turned on from 4:00pm till midnight or for 8 hours.
8 hours X 60=480 minutes that the 2nd hose was turned on.
480 X 8 gallons/minute=3,840 gallons of water from 2nd hose.
We know that 1st. hose was on for at least 7 hours.
7 hours X 60 X 5=2,100 gallons of water from 1st. hose
3,840 + 2,100=5,940 gallons from both hoses
7740 - 5940 =1,800 gallons to come from 1st hose.
1800/(60 X 5)=6 hours that the 1st. hose was running after 4:00pm
Therefore the hose was running till: 4 + 6=10:00pm. which is the time it was shut off.
+2498 i think it cannot be determined from the information given above there is can be many answers
At 9:00 am, an empty water tank begins to be filled with water flowing through a hose at a rate of five gallons per minute. Seven hours later, water flowing through a second hose also starts to fill the tank at a rate of eight gallons per minute. Some time later, the first hose is turned off but the second hose continues to be used to fill the tank. At midnight the 7740-gallon tank is finally full. At what time was the first hose turned off?
The second hose was turned on from 4:00pm till midnight or for 8 hours.
8 hours X 60=480 minutes that the 2nd hose was turned on.
480 X 8 gallons/minute=3,840 gallons of water from 2nd hose.
We know that 1st. hose was on for at least 7 hours.
7 hours X 60 X 5=2,100 gallons of water from 1st. hose
3,840 + 2,100=5,940 gallons from both hoses
7740 - 5940 =1,800 gallons to come from 1st hose.
1800/(60 X 5)=6 hours that the 1st. hose was running after 4:00pm
Therefore the hose was running till: 4 + 6=10:00pm. which is the time it was shut off.
+129850 Well....at midnight, the second hose has been operating for 8 hours.......so....it must have put
8hrs x 60 min x 8 gal/min = 3840 gal of water into the tank
So......the first hose must have put 7740 - 3840 = 3900 gal of water into the tank.....so the number of hours it operated can be found as :
Hrs operated x 60min x 5 gal/min = 3900 gal
Hrs operated x 300 gal = 3900 gal
Hrs operated = 13 [after 9AM]
So....it was turned off at 10 PM
