Try this without googling the answer.. also please try to justify your assumptions if any ?
A party of four travelers comes to a rickety 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 travelers 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 takes 10 minutes to cross the bridge. If two travelers cross together, they walk at the speed of the 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?
(2+1)+(5+1)+10=19 min
ReplyDeleteHello arun,
ReplyDeleteplease try to optimize your solution.
(2+1)+(10+2)+2=17 !!
The shortest travel time is 17 minutes.
ReplyDeleteFirst, 1 minute guy and 2 minute guy go over, and 1 minute guy comes back. TOTAL TIME = 3 minutes
Next, 10 minute guy and 5 minute guy go over, and 2 minute guy comes back. TOTAL TIME = 15 minutes.
Lastly, 1 minute guy and 2 minute guy go over together. TOTAL TIME = 17 minutes.