4 People Bridge Crossing Puzzle | MindYourLogic Bridge Crossing Puzzle

In 4 People Bridge Crossing Puzzle, a bridge will collapse in 17 minutes. 4 people want to cross it before it will collapse. It is a dark night and there is only one torch between them. Only two people can cross at a time. “A” takes a minute to cross. “B” takes 2 minutes, “C” takes 5 minutes and “D” takes 10 minutes. How do they all cross before the bridge collapse?

Here we have provided information for the solution of Crossing the Bridge Puzzle :

Time in which bridge will collapse = 17 mins

Number of people who wants to cross the bridge = 4 people

Number of the torch they have = 1

Time taken by A to cross the bridge = 1 minute

Time is taken by B to cross the bridge = 2 minutes

Time is taken by C to cross the bridge = 5 minutes

Time is taken by D to cross the bridge = 10 minutes

    Move                                 Time

A & B Cross with torch          2 min

A return with torch                1 min

C & D Cross with torch        10 min

B return with torch                2 min

 A & B cross with torch          2  min

          Total time                 17 min

A & B crosses the bridge in 2 mins and A returns with the torch in 1 min, so the total time taken by now is 3 min. 

Time left before the bridge collapsed = 14 mins

C & D crosses the bridge in 10 mins and B returns with the torch in 2 mins, so the total time taken by now is 15 min. 

Time left before the bridge collapsed = 2 mins

Now, A & B were only left out and the time left before the bridge collapsed in 2 min but the maximum time taken by A & B to cross the bridge is 2 mins as the time taken by A is 1 min and by B is 2 mins. 

Hence A, B, C, and D four will cross the bridge within 17 mins.

By carefully planning their moves, all four people—A, B, C, and D—successfully cross the bridge in exactly 17 minutes, just before it collapses. This puzzle demonstrates how strategic thinking and time management can solve a seemingly impossible situation.