Analysis of the Puzzle:

Analysis of the Puzzle:

1. **Water starts at Tank A:**
– The water will first flow into Tank B since it’s directly connected to Tank A.

2. **Path from Tank B:**
– Water flows from Tank B into Tank C. However, Tank C has an open pipe leading to Tank J before it can fill up.
– Since Tank J leads to Tank K and Tank K leads to Tank L, the water would continue flowing without filling Tank C immediately.

3. **Flow from Tank C:**
– Water from Tank C can also flow into Tank D. However, Tank D has an open pipe leading to Tank G before it can fill up.
– Tank G will attempt to fill up but is blocked by the connection to Tank F, meaning Tank F won’t receive water.

4. **Blocked Paths:**
– The water cannot go into Tank H or Tank I immediately because they are not connected directly from Tank A.
– Tank E will not receive water immediately because the flow to Tank F is blocked.

Conclusion:

The water from Tank A will flow through Tank B, into Tank C, and then into Tank J. Tank J will fill up first because the path continues downward into Tanks K and L without being blocked, but Tank J is the first one that can actually contain water without an outlet.

Thus, **Tank J will fill up first**.