Brain Teaser

[Neapolitan Ice Cream]

 

[lanejudy]

F

 

[Lewisc]

G

 

[georgina]

I don't claim to be a genius, but after looking at it, I think lanejudy is correct with F.

 

[Tom_E_D]

I agree with F.

Reasoning: The tank with the lowest top should fill first, provided that it is getting water. H has the lowest top but has no water source. The pipe from L to H is blocked. G has the second lowest top, but its only water source would be D, except that D has no water source. The pipe from C to D is blocked. F has the third lowest top and thus will fill first. The fact that its water from L comes up from the bottom doesn't matter.[/ISPOILER]

 

[Cadiewampus]

Are we going to assume water can not flow up the pipes? If so then I agree with F. If not I am going with K. The water in J will never get high enough to flow into L and then on to F. It will go out the hole at the base of J into I and then to K. Guess it really depends on the volume of water flow into A

 

[Moliphino]

Are we going to assume water can not flow up the pipes? If so then I agree with F. If not I am going with K. The water in J will never get high enough to flow into L and then on to F. It will go out the hole at the base of J into I and then to K. Guess it really depends on the volume of water flow into A

It will start flowing up the tube into I first before the tube to L, but it wouldn't get high enough to actually flow into the I tank before it would flow into L.

 

[BrianL]

Are we going to assume water can not flow up the pipes? If so then I agree with F. If not I am going with K. The water in J will never get high enough to flow into L and then on to F. It will go out the hole at the base of J into I and then to K. Guess it really depends on the volume of water flow into A

The water will keep a consistent level as it fills the attached tanks. For pipes that go up, it won't come out of the pipe until water in the tank is also as high. Tank J and the pipe to its left will fill up to the point where it can start falling toward L. It will do that until it is full below that point and J can start rising again.

 

[sam_gordon]

I agree with F.

For @Cadiewampus, water will flow "up" the pipe as the source tank gets to the same level.

D, E, G, H have no way to get water to them. Water flows from A>B>C>J>L>F. They will fill (overflow) in reverse order.

No water gets to I (and therefore K) until J is just about full.

 

[prairie_girl]

It’s G

It can’t be F because it has no way for water to enter it

 

[Tom_E_D]

I agree with F.

For @Cadiewampus, water will flow "up" the pipe as the source tank gets to the same level.

D, E, G, H have no way to get water to them. Water flows from A>B>C>J>L>F. They will fill (overflow) in reverse order.

No water gets to I (and therefore K) until J is just about full.

I was going to reply to sam_gordon and point out that the water overflowing from the top of F will fill G before L, or any of the other tanks, fill when I realized how nonsensical this 2-dimensional diagram is. Is H the only tank that is on the ground? Or is H even on the ground? I seem to see a thin space below it. What's holding the tanks up? H? Even if H could use the pipes to hold up all the tanks that are connected to it by pipes, it isn't connected to G at all. G seems to be hanging in midair. The best I could come up with to make sense of it is that all the tanks and pipes are connected to the far (back) wall. and perhaps the near (front) wall. In that case, if there is space under H, and space to the right of F, then H will be the second tank to fill up. But, boy, is that ever making a lot of assumptions.

 

[chrisney]

View attachment 984148

Agree with G

 

[sam_gordon]

Agree with G

How? In order for water to get to G, it's got to get into D. But if you look close, the pipe from C to D doesn't allow water to get into D.

 

[sam_gordon]

It’s G

It can’t be F because it has no way for water to enter it

What's blocking the water from getting to F? Here's the water path: A>B>C>J>L>F

ETA: Animation of the water flow:

 

[prairie_girl]

What's blocking the water from getting to F? Here's the water path: A>B>C>J>L>F

ETA: Animation of the water flow:

My bad! I saw a solid line somewhere where there wasn’t one.

 

[jimmymc]

Giving my engineering answer, it depends on the size of the pipes and buckets, viscosity of the liquid, and flow rates. It will most likely be A or F.

 

[_19disnA]

OP didn't make this one up, it is posted on the internet. Anyone who wants to see the explanation for the right answer can easily look it up.

 

[georgina]

Giving my engineering answer, it depends on the size of the pipes and buckets, viscosity of the liquid, and flow rates. It will most likely be A or F.

Gee, based on the picture, I assumed it was water, and the location of the pipes and size of the buckets are as shown.

 

[Moliphino]

Gee, based on the picture, I assumed it was water, and the location of the pipes and size of the buckets are as shown.

But if the faucet is flowing more into A than can flow out the pipe into B, the A bucket will overflow before B fills up.

 

[BrianL]

But if the faucet is flowing more into A than can flow out the pipe into B, the A bucket will overflow before B fills up.

I think for purposes of the exercise, it can be assumed that all pipes are the same diameter. They're not asking for the math, just the reasoning.