A student is getting ready to take an important oral examination and is concerned about the possibility of having an "on" day or an "off" day. He figures that if he has an on day, then each of his examiners will pass him independently of each other, with probability .8, whereas if he has an off...
This problem comes from Sheldon Ross's book "A First Course in Probability (6th ed)."
There are 5 hotels in a certain town. If 3 people check into hotels in a day, what is the probability that they each check into a different hotel?
Attempt at a solution:
There are 5C3 = 10 different...