Conditional Probability
You are on a game show in which there are 3 doors. Behind one door is a pot of gold, but the other doors contain rocks. You choose door #1.
The host of the game show pulls a lever which will randomly open one of the two doors you didn't choose. To your relief, door #3 was opened and turned out to have rocks!
The host offers you a decision: stick with door #1, or switch to door #2. To maximize the probability that you get the gold, what should you do?
by
Eli Ross
In general, John and Amy are right about the weather with probabilities 70% and 60%, respectively and independently. Given the conversation above, what is the probability it rains tomorrow in their home of Brilliantia?
by
Eli Ross
A family has two children. Given that one of the children is a boy, and that he was born on a Tuesday, what is the probability that both children are boys?
Assume that the probability of being born on a particular day of the week is and is independent of whether the child is a boy or a girl.
by
Calvin Lin
Zeb's coin box contains 8 fair, standard coins (heads and tails) and 1 coin which has heads on both sides. He selects a coin randomly and flips it 4 times, getting all heads. If he flips this coin again, what is the probability it will be heads? (The answer value will be from 0 to 1, not as a percentage.)
by
Eli Ross
Two fair dice are rolled, and it is revealed that (at least) one of the numbers rolled was a 4. What is the probability that the other number rolled was a 6?
Note: You are not told which of the numbers rolled is a 4.
by
Sandeep Bhardwaj