OK, #1 flows into #2 and #3. #3 can't flow into #4 because the tube is blocked, so #4 will never get a drop of water in it. The other drain out of #3 into #5 is also blocked. #5 will never get water in it.
#2 is blocked from draining into #6, so no water will ever get in #6. #2 can drain into #7, but there's a hole in the bottom of #7, so it will never fill.
That leaves cups #2 and #3, and of course, #1. Since the water flowing out of #1 into #2 and #7 will be draining out on the floor, none of them will fill to the top. The outlet from #1 to #3 is lower than the outlet from #1 to #2, so #3 SHOULD fill first, since #2 is draining into a bottomless cup (#7).
So, my answer is #3. Did I figure it out? Or am I to be counted among the great unwashed 99%? LOL! (It makes sense to me, but a lot of things make sense to me that other people say are crazy, so who knows?)
Look again.The other drain out of #3 into #5 is also blocked. #5 will never get water in it.
The first time I saw this I laughed until I almost cried. A neighbor I used to help fed cattle until he was almost 80. He chain smoked non filtered camels.stress on the ranch
Look again.
I can't find it now, but seems like #3 was blocking #4 at the #3 outlet to #4.Look again.
You are absolutely right, I missed that.I can't find it now, but seems like #3 was blocking #4 at the #3 outlet to #4.
#3 is blocked from filling #5 at the #5 inlet (I think I recall that).
On the left side cups, that only leaves #3 that can fill at all from #1. On the right side cups, #6 is blocked from #2, and #7 has a hole in the bottom, so only #2 can hold water. #2 can't begin filling until after #3 is full and #1 is up to a level to flow to #2. #2 will never fill.
So, #3 is the first one to fill. It is also the only one that will ever fill (until somebody calls a plumber). In fact, the problem may have been easier to solve if the question had been "Which cup is the only one that can fill to the top?".