Thread: Bridge Crossing

Problem Statement:

A party of four travelers come to a ricety bridge at night. The bridge can hold the weight of at most two of the travelers at a time, and it cannot be crossed without using a flashlight. The tavelers have one flashlight among them. Each traveler walks at a different speed: The first can cross the bridge in 1 minute, the second in 2 minutes, the third in 5 minutes, and the fourth taes 10 minutes to cross the bridge . If two travelers cross together, they walk at the speed of slower traveler.

What is the least amount of time in which all the travelers can cross from one side of the bridge to the other.

Solution:

To minimize the total time, we need to send those traveler together who takes more time.

- first(1) and second(2) traveler go acrooss (2 minutes)
- first traveler(1) goes back (3 minuttes)
- thord(5) and fourth(10) traveler cross (13 minutes)
- Second Traveler (2) goes back (15 minnutes)
- First(1) and second(2) traveler cross (17 minutes)

Ans: 17 minutes