Hupp31

06-03-2010, 09:06 PM

I ran across this brain teaser and was going to dismiss it post haste. However, it struck me that this is a real life scenario that the military faces all the time. I'm guessing that some similar number crunching is going on with the oil spill in trying to calculate various probabilities and possibilities there.

I can hold my own up through Trig, but I'm still waiting for that damn train from Topeka to pass the one from Oshkosh somewhere near Mt. Rushmore. I don't even know how to begin the following as I always sucked at probability - unless the dice were loaded or the coin had 2 heads. Any thoughts?

***

You are the Intelligence Officer for a Special Ops unit planning to assault a terrorist hideout and rescue several kidnapped citizens of your country. Your Commanding Officer has asked you to calculate the probability that the kidnapped citizens will be released as a result of the assault.

Construct a probability tree considering the following:

1. The success or failure of the Special Ops Unit reaching the terrorist hideout.

2. An attempt by the terrorists (yes or no) to booby-trap the kidnapped citizens with explosives.

3. The killing of the kidnapped citizens (none, some, all) during the rescue attempt.

You have carefully analyzed the situation and determined there is a .9 probability of the Special Operations Unit reaching the terrorist hideout and a .3 probability that the Kidnapped citizens will be booby-trapped with explosives.

If the kidnapped citizens are booby trapped, there is a .4 probability that all will be killed during the assault, a .4 probability that some will be killed, and a .2 probability that none will be killed.

If the kidnapped citizens are not booby-trapped, there is a .6 probability that none will be killed, a .2 probability that some will be killed, and a .2 probability that all will be killed.

Calculate the total probability that all of the kidnapped citizens will be rescued, and provide any other finding you believe relevant.

***

I was fine until the part about the "probability tree" (third sentence). Is that anything like an oak or maple?

Would anyone out there dare hazzard a guess? How would one even begin to tackle this?

Thanks,

Phil

I can hold my own up through Trig, but I'm still waiting for that damn train from Topeka to pass the one from Oshkosh somewhere near Mt. Rushmore. I don't even know how to begin the following as I always sucked at probability - unless the dice were loaded or the coin had 2 heads. Any thoughts?

***

You are the Intelligence Officer for a Special Ops unit planning to assault a terrorist hideout and rescue several kidnapped citizens of your country. Your Commanding Officer has asked you to calculate the probability that the kidnapped citizens will be released as a result of the assault.

Construct a probability tree considering the following:

1. The success or failure of the Special Ops Unit reaching the terrorist hideout.

2. An attempt by the terrorists (yes or no) to booby-trap the kidnapped citizens with explosives.

3. The killing of the kidnapped citizens (none, some, all) during the rescue attempt.

You have carefully analyzed the situation and determined there is a .9 probability of the Special Operations Unit reaching the terrorist hideout and a .3 probability that the Kidnapped citizens will be booby-trapped with explosives.

If the kidnapped citizens are booby trapped, there is a .4 probability that all will be killed during the assault, a .4 probability that some will be killed, and a .2 probability that none will be killed.

If the kidnapped citizens are not booby-trapped, there is a .6 probability that none will be killed, a .2 probability that some will be killed, and a .2 probability that all will be killed.

Calculate the total probability that all of the kidnapped citizens will be rescued, and provide any other finding you believe relevant.

***

I was fine until the part about the "probability tree" (third sentence). Is that anything like an oak or maple?

Would anyone out there dare hazzard a guess? How would one even begin to tackle this?

Thanks,

Phil