Five Workers Bridge Crossing Puzzle | MindYourLogic Bridge Crossing Puzzle

Five workers need to cross a narrow bridge at night using a single lantern. Each worker has a different crossing speed, and the lantern must be carried back and forth. The challenge is to determine the minimum total time required for all five workers to cross the bridge. The minimum total time required for all five workers to cross the bridge is 26 minutes.

Conditions:

Worker A: 1 minute
Worker B: 2 minutes
Worker C: 5 minutes
Worker D: 8 minutes
Worker E: 12 minutes

The bridge can hold at most two workers at a time.
The lantern must be carried by those crossing the bridge.

Objective:
Find the minimum time required for all five workers to cross the bridge.

Steps to Cross the Bridge in Minimum Time:

First Crossing:

Worker A (1 minute) and Worker B (2 minutes) cross the bridge together with the lantern.
Time taken: 2 minutes (the time of the slower worker, Worker B).

Lantern Return:

Worker A (1 minute) returns with the lantern.
Time taken: 1 minute.
Total time elapsed: 3 minutes.

Second Crossing:

Worker D (8 minutes) and Worker E (12 minutes) cross the bridge together with the lantern.
Time taken: 12 minutes (the time of the slower worker, Worker E).

Lantern Return:

Worker B (2 minutes) returns with the lantern.
Time taken: 2 minutes.
Total time elapsed: 17 minutes.

Third Crossing:

Worker A (1 minute) and Worker C (5 minutes) cross the bridge together with the lantern.
Time taken: 5 minutes (the time of the slower worker, Worker C).
Total time elapsed: 22 minutes.

Final Step: Lantern Return and Last Crossing:

Worker A (1 minute) returns with the lantern to bring Worker B.
Time taken: 1 minute.
Total time elapsed: 23 minutes.

Last Crossing:

Worker A (1 minute) and Worker B (2 minutes) cross the bridge together with the lantern.
Time taken: 2 minutes (the time of the slower worker, Worker B).
Total time elapsed: 26 minutes.

Conclusion:
By following this strategy, all five workers successfully cross the bridge in a total of 22 minutes. The strategy minimizes the total crossing time by efficiently managing the lantern and carefully pairing workers to balance the crossing time with the return trips.