Time and amounts of water

Karlene

New member
Joined
May 16, 2019
Messages
1
Please can anyone help me with this question?
It would take 120 minutes to fill a swimming pool using water from 5 taps.
How many minutes will it take to fill the pool if only 3 taps are used?
State one assumption you made in working out your answer.
My answer was as follows:-
5 taps - 120 mins
1 tap - 120/5 = 24 mins
3 taps - 24 x 3 = 72 mins
I assumed that the same amount of water would flow from each tap.
But my answer can't be right because it would take longer for 3 taps to fill the pool than 5.
I'm confused!
 

Subhotosh Khan

Super Moderator
Staff member
Joined
Jun 18, 2007
Messages
19,024
Please can anyone help me with this question?
It would take 120 minutes to fill a swimming pool using water from 5 taps.
How many minutes will it take to fill the pool if only 3 taps are used?
State one assumption you made in working out your answer.
My answer was as follows:-
5 taps - 120 mins
1 tap - 120/5 = 24 mins............................ No!

assuming each tap is pouring in at the same rate
With only one tap open out of 5 - you will pour in 1/5 th of water in a given time.
So it will take 5 times more time to fill in with one tap.

Now continue with similar logic......


3 taps - 24 x 3 = 72 mins
I assumed that the same amount of water would flow from each tap.
But my answer can't be right because it would take longer for 3 taps to fill the pool than 5.
I'm confused!
 

HallsofIvy

Elite Member
Joined
Jan 27, 2012
Messages
5,267
The rate at which one tap fills a tank is in "gallons per min". The time, minutes, is in the denominator! You have your fractions "upside down". It will take 5 times as long, not 1/5 as long, 5*120= 600 minutes, not 24 minutes, for one tap to fill the tank. 3 taps will take 5/3(120)= 600/3= 200 minutes.
 
Top