- Oct 17, 2011
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First rule of bridge challenge: Your first response to the bridge challenge is just to reply with your answer in terms of minutes, no other explanation of details. Other comments not directly related to your solution are okay.
Second rule of bridge challenge: later in thread, we'll open it up to larger discussion.
Third rule of bridge challenge: No this doesn't have much to do with Physical & Life Sciences, but I may be able to make an analogy later that will bring it closer to topic.
Bridge situation:
An improbably rickety bridge can only be crossed by at most two people at a time.
It is also dark and there may be grues on the bridge. You need a torch to cross the bridge (but both sides are safe).
There is only one torch. (so when it is carried across, someone will have to bring it back)
Four people need to cross the bridge (and all 4 start on the same side):
A speedy person who can cross the bridge in 1 minute.
A fit person who can cross the bridge in 2 minutes.
A soft person who can cross the bridge in 5 minutes.
An infirm person who can cross the bridge in 8 minutes.
When two people travel together, they can only go as fast as the slower person. (e.g. if speedy and infirm go together, it takes 8 minutes to cross).
Bridge challenge:
What is the shortest amount of time required to get all 4 people across the bridge?
Last rule of bridge challenge: See First Rule! First answers should only provide the time in minutes, not a detailed description of the solution.
Second rule of bridge challenge: later in thread, we'll open it up to larger discussion.
Third rule of bridge challenge: No this doesn't have much to do with Physical & Life Sciences, but I may be able to make an analogy later that will bring it closer to topic.
Bridge situation:
An improbably rickety bridge can only be crossed by at most two people at a time.
It is also dark and there may be grues on the bridge. You need a torch to cross the bridge (but both sides are safe).
There is only one torch. (so when it is carried across, someone will have to bring it back)
Four people need to cross the bridge (and all 4 start on the same side):
A speedy person who can cross the bridge in 1 minute.
A fit person who can cross the bridge in 2 minutes.
A soft person who can cross the bridge in 5 minutes.
An infirm person who can cross the bridge in 8 minutes.
When two people travel together, they can only go as fast as the slower person. (e.g. if speedy and infirm go together, it takes 8 minutes to cross).
Bridge challenge:
What is the shortest amount of time required to get all 4 people across the bridge?
Last rule of bridge challenge: See First Rule! First answers should only provide the time in minutes, not a detailed description of the solution.
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