Which container will be full first?

My ans is 1. Although tank 5-2 is blocked, the hole that connects tank 1-5 is straight, hence, before tank 5 could be fully filled, the hole in tank 1 will be quickily filled up with the running water when the water in tank 5 reaches the hole level, hence, tank 1 will be full first.

5 Water will only flow to 1 and 5. Water can't flow from 5 to 2 since the opening is closed. Without water in 2, tanks 4, 3 and 6 will not get water either. So water will only flow from 1 to 5. Out of the two 5 will fill up first.

ah trick question, i see what you did there

5 as other ways r BLOCKED

Obviously 5

2

5

Container 4

5

5 ofc