Hey Sup Forums I have a test for you. Prove you are smart

Hey Sup Forums I have a test for you. Prove you are smart.

-2 h

69. Lol meme dank joke

wrong!

It takes 8h to fill the tub (shit at math btw)

Can't be solved. Too many variables

it would never fill since B is draining the water

every 8 hours it will fill 2 hours worth of 1.
24 hours

about 14 gallons

it's already full...

18hrs

Why does the bathtub take so fucking long to fill? That is the real question.

48 hours. Simple.

What's the logic/math behind that? I found another answer.

how's that? explain.

Lets say the bathtub can hold 1L of water.
1000/6=166.67
1000/8=125
166.67-125=41.67
1000/41.67=21.4 hours

Hold the door

This looks correct. as long as we aren't including fluid dynamics and pressure into the mix

correct user

wrong, I did the same first time I tried to solve it.

24 hours.

We are not including fluid dynamics and pressure. Explain please. I got another answer.

Lowest common denominator of 8 and 6 is 24 so let's arbitrarily make that the volume of the tub. If the the tub is filled in 6 hours that means it is filling at a rate of 4 per hour. If it empties in 8 hours that means it is emptying at 3 per hour. That's a net of 1 filled per hour. So it would take 24 hours to fill the tub.

After 8 hrs it would've drained once while filling 6 + a third again. So 3 times over 8hrs, 24

...

Is it 24 hours?If we are talking real world it would never fill as the pressure would increase as the tub fills meaning it would drain faster.
24 hours?

18 h

Since B is a drain and not a tap, Id say it'll take about 6 hours.

Volume = V
Filling rate = 1/6Vhr^-1
Emptying rate = 1/8Vhr^-1
When both are open:
1/6V*h- 1/8V*h = V where V = volume filled and h = time elapsed in hours
h(1/6-1/8) = 1
h=1/(8/48-6/48)
H=48/2 = 24hrs

Every 6 hours tap 1 fills the tub. But in 8 hours the tub is drained by tap 2. Then the extra 2 hours worth of flow that tap 1 puts out beyond 6 hours (8 hours) is extra water. If the tub fills normally in 6 hours without tap 2 open then it would take 3 times 8 hour intervals to completely fill the tub.

x is the amount of time it would take to fill this shit up.

1/6*x-1/8*x=1
1/24*x=1
x=24 hours

I got 32 hours. I divided 6/8 and got 0.75 or 75%. And then I thought the bathtub filled 100% but emptied 75% so it remained only 25% full. And then I did something like this. 8h . . . 25% ; xh . . . 100% . And then I did that rule with numbers (8*100)/25, and got 32h.

You are all making the task more complex than it needs to be.
24 hours

Thanks!

9 + 1 + 1 = 24 hours

(1/6)-(1/8) is how fast water gets in when both valves are open. Equals 0.041(6). Equals 1/24.
So the answer is 24 hours.

Is anyone taking into account the siphoning effect on the rate of drainage?

is the simplest solution ITT

You are making it too complex too.
check

A=1/6h B=1/8h

1/6h - 1/8h = 4/24h - 3/24h
4/24h - 3/24h = 1/24h

24h without engagement

Can't help but make it an algebra problem. It's just how my brain processes problems like this.

assuming we are taking the pressure into account it would take more than 24 hours since the tub would be filling faster than it would normally drain causing more time where the box is more than averagely full. so yeah op is a faggot

Didn't properly read your math anons. I don't think in equations, so it seems simpler to me to write the problem out. I can do maths but I don't read numbers as well as I do ideas. You are right. The solution is probably simpler the way you put it

> X IS THE VOLUME
>A IS 6
>B IS 8
>B IS 1/3 SMALLER THAN A
>SO 1/3 OF WATER WILL REMAIN EVERYTIME
>IT WILL TAKE 3 TIMES MORE HOURS TO COMPLETE THE TASK
3*6=18

Retard alert!

6/8=1/3

Is it bait?

wrong. We have already established that it would take 3 times 8 hours user. read the thread

Ok, thanks all for your answers! Anyone has more problems like this?

This

He is saying that 2/3 drains out while 1/3 remains in the tub.

dont think so, as far as i see you guys are only saying stupid things, 8h to empty and 6h to fill means you have a bigger pipe pouring than emptying, then u get how smaller the pipe is, and then its done.

8/6= 1,3
6/3=2
8/4=2

Every 8 hrs it's empty but it only takes 6 hrs to fill it so +2hrs of water for every 8 so 24 I believe if I'm correct that means the b drain is 1/4 smaller of a tube

Gay and wrong. Nothing wrong with being gay though

no bro, if you put 6 litres of water you have 1 litre each hour, then u empty the tub and you empty at a speed of 0,66 litres an hour.

Meaning that every hour you got 0,33 litres, then you have 1 litre after 3 hours, up to 6 litres of water it takes 3*6=18

He is wrong by not converting time(6h) into volume/hour (1/6 per hour).
Then it is clear that 1/6 fills in while 1/8 leaks out, that leaves 1/24 of volume per hour.

If you pump Sup Forums into Sup Forums and let the original Sup Forums flow out at a slightly slower rate you get fine /h/ material.

It's 3/4's not 1/3
6 and 8 can only be reduced by 2
So 6/8 =3/4

It's trips, so he can't be wrong, even if it is mathematical nonsense.

We got a wiener here!

Only Asians could over complicate a problem using maths. Being good at maths doesn't help you see what the problem is. 24 hours master race here!

This guy is bang on

After 8 hours 1 whole tub has drained. However it takes 6 hours to fill it, so in that time it has filled that much plus an extra 2 hours worth of filling time. If it takes 6 hours to fill then in the 2 extra hours it fills one third. Times these 8 hours by 3 to get 24 hours.

no, it takes less to fill than it takes to empty, and B is smaller than A

also explain, i think you are wrong but maybe is just me

Fills 1/6 bathtubs per hour (b/h)
Loses 1/8 b/h
1/6-1/8
Resultant fill rate is 1/24 b/h
Therefore: 24 hours per 1 bathtub

6 hours to fill 1 bathtub.
8 hours to drain 1 bathtub.

48 hours to fill 8 bathtubs.
48 hours to drain 6 bathtubs.

48 hours to fill 2 bathtubs with both valves open.
24 hours to fill 1 bathtub with both valves open.

mfw reading all this nonsense.
How the fuck will it take 24h to fill for god sake you guys should go back to high school

What is your answer?

outlet flow is not linear and is proportional to the square root of the height in the tank. if i still had a cracked copy of mathcad i'd make a pretty graph

take the plug out of your bath and see how long it takes to fill.

12h you dumb fuck

It's not as much gibberish in my head.
I once had a teacher who always wanted me to show my work or she'd fail me and claim I was cheating. I explained it to her one time , she couldn't grasp that I could find quicker methods and obtain the correct answer so she stopped trying to make me show my work....
>I do math while I drive for fun
>my job requires me to be able to give etas within 30 minutes up to a week away

This is the simplest solution imo.

New problem!

The distance between cities A and B is 720 km. There is a train going from A to B at the speed of 80 km/h. 2 hours after its departure from B to A departs another train that goes 60 km/h. How many hours after the first train's departure would the two trains meet?

I think it takes 9 hours but I flunked 9th grade. so that's makes sense to me

Does this mean you are Asian? In that case I wish you the best of luck in the maths field. Just leave the driving to someone else ok buddy.

Its 8/6 = 1.33 hours approximately

After 2 hours the distance between trains is 560.
560km/(80+60)km/h=4h
The answer is 6 hours.

24 hours

I have a better problem. THE JEWISH QUESTION
If it can be solved with maths I would like to see it

18 since every hour you have:

Lets say you have 18L of water
it takes 6 hours to fill it
so it takes 3L each hour
then you have to empty 18L in 8 hours so it empties 0,6L each hour, it means that pipe B is 2/3 of pipe A size meaning it takes 4/3 the time to empty it than to fill it
if every hour you have 0,3L you have 1/3 of whatever A fills, meaning it takes 3 hours to fill 1 hour of A

So 3 hours to do the job of 1 means every hour you have 3 hours, 6x3=18

1 full bath tub = 4full bath tubs(4*6) - 3 empty bathtubs(3*8)

4-3 = 1

4

Well done user

x jews + 1 hitler = (x - 6000000)jews

The tub is filled by 25% every 6 hours, so the answer is 24 hours assuming we are ignoring pressure.

nope.

Good answer user.

Kek no I'm not a Asian no worries there I have a soul

Yay. Those were calculus problems in my 5th class.
When do americans solve those in school?

80x2=160
720-160=560 remaining
4×80=320 + 4x60=240 =560
So 4 unless I misread it I am tired

>560

Did someone take a bath in the tub while it was filling/draining? Did they splash? Piss in the water?

you forgot the two hours.

...

>shit at math btw

Yeah, we can see that.

you can't fill it up. It will always drain.

It is filling up faster than it is draining, so at some point it will fill up the bath then overflow.

if you drain it for 6 hours, 20% remain. so every hour, 1/5th of the bathtub gets filled.

answer is 30 hours.