# Puzzle | Human Zombie

• Difficulty Level : Easy
• Last Updated : 18 Jan, 2023

This is a problem in which 4 people are their s1, s2, s3, s4 and there is a Bridge.These 4 people came to know that zombie will going to attack them after 17 minutes.Now the situation is like there is a lantern and at a time at most 2 people can cross the bridge but only with lantern and now here are the time that each person takes to cross bridge:

s1–> 1 minute
s2–> 2 minutes
s3–> 8 minutes
s4–> 10 minutes

Now we need to find out that whether is it possible that all 4 people will reach the other side of the bridge and cut the rope in 17 minutes.

Explanation:
We need to sort them in ascending order of time i.e 1, 2, 8, 10 then we will send 1 & 2 so total time taken to cross bridge is 2 min and time to come back to start point by s1 is 1 min.
Now we will take next 2 i.e 10 & 8 minutes people and will send them so total time required would be 10 minutes
So overall its 1+2+10=13 minutes.
Now s2 with time of 2 minutes will come back with lantern so total time is 13+2 minutes.
And then s1 & s2 will go back 15+2 minutes.

In this way everyone is able to cross bridge and then they will close the bridge.

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