Which Reseptacle Fills First?

Depends how quick the flow in is, it could be cup 1 if the flow is fast enough.

 

4

 

nope. 5

 

The tap depicts a slow drip.
If drip is slow enough, the ambient temperature high enough and the humidity low enough and assuming the structure is open to the atmosphere - none of them will fill : o )

 

3

 

possibly none actually depending on flow rate.

 

But if the flow is reasonable, I reckon number 4

 

not if the flow stops once it hits the top of the pipe.

 

Three.

 

Three.

 

Easy. 9.

 

three is blanked off at the bottom.

 

3. Just seen blocked off pipes..... Doh

 

5

 

No water can get into 5, look closer