4 Soilders Bridge Crossing Puzzle | MindYourLogic Bridge Crossing Puzzle

Four soldiers need to cross a bridge at night. The bridge is unstable and will collapse in 17 minutes. The only source of light is a single flashlight that must be carried by the soldiers while crossing. The bridge can hold a maximum of two soldiers at a time. Each soldier has a different crossing speed:

Soldier A: 1 minute
Soldier B: 2 minutes
Soldier C: 5 minutes
Soldier D: 10 minutes
The soldiers must develop a strategy to cross the bridge within 17 minutes before it collapses.

Steps
Initial Crossing:

Step 1: Soldiers A and B (the two fastest) cross the bridge together with the flashlight. This takes 2 minutes.
Soldier A returns with the flashlight, taking an additional 1 minute.
Total time so far: 3 minutes.
Second Crossing:

Step 2: Soldiers C and D (the two slowest) cross the bridge together with the flashlight. This takes 10 minutes.
Soldier B returns with the flashlight, taking an additional 2 minutes.
Total time so far: 12 minutes.
Final Crossing:

Step 3: Soldiers A and B cross the bridge together again with the flashlight. This takes 2 minutes.
Total time so far: 17 minutes.

Conclusion
By carefully planning the crossings, all four soldiers successfully cross the bridge just in time, within the 17-minute limit before the bridge collapses. This solution effectively manages the constraints of time, the flashlight, and the varying speeds of the soldiers, ensuring a safe crossing for all.