I agree, tank 1, how’s the water suppose to get in tanks 3 & 4?
Two.
If the flow IN to tank 1 is the same as the flow in to tank 2, then 2 will fill first. If the flow in to tank 1 exceeds the flow in to tank 2, then 1 will fill first. Of course that all depends on whether the test stops immediately upon the first full tank.
The correct answer is tank 2.
The pipe is closed off and cannot flow into tank 3 and 4.
All who answered tank 2 are WINNERS.
SO… remove the trick(?) blockage at the drain at tank #2 and what is the answer?
Yep! I didn’t see that when I was looking at it on my phone.
Remove the block and it’s 3&4 at the same time.
And driving!
This was in a different message board. The blockage was at the inlet to tank 3, not the outlet of tank 2. It was harder to notice.
If there was no blockage, tank 3 would fill first, with tank 4 slightly behind.
When you do an inspection… look at things very carefully.
Dammit, John, you got me.
Do I have to refund the inspection fee?!
Except as noted in post #22
The quiz is rigged. :p;-)
The flow is shown. It’s only dripping.
That just symbolizes running water. Drips would be in a line, not that wide apart.
lol good one
Tank 2 will fill first
Three
None will fill first because as a home inspector I would point out the dripping faucet as a defect for repair. A qualified plumbing contractor repairs the leak and stops it before any tank is filled. 
I say one if water flow is fast enough. Meaning that it fills faster than it drains.