This is a question my friend asked me last night, it's a probabilty problem. hope it helps you :)
Q: "An oil drilling venture involves drilling four wells in different parts of the country. For each well, the probability that it will be profitable is 0.10, and the probability that it will be unprofitable is 0.90. If these events are independent, what is the probability of drilling of at least one unprofitable well?"
assuming you know the basics of probability, I'll be using the Binomial Distribution.
n = 4, since there are 4 wells
p = 0.9, the probability of an unprofitable is 0.9
I couldn't figure out how to type N choose K in MS Words, so i'll just post the pic of my crappy hand writing version. I skipped some steps, but it's really just plugging in the numbers and crunch your TI-84
and also, since we're looking at P(unprofitable well >=1), you're suppose to integrate it from 1-4, i'm too lazy to do that, so i just did
P(unprofitable well = 1) + P(unprofitable well = 2) + P(unprofitable well = 3) + P(unprofitable well = 4)
sorry for my laziness
Answer after jump :)
