Friday

December 19, 2014

December 19, 2014

Posted by **Sakura1** on Tuesday, March 11, 2014 at 8:56am.

1 Alice has five coins in a bag: two coins are normal (i.e., fair with one face Heads and the other face Tails), two are double-headed (i.e., both sides are Heads), and the last one is double-tailed (i.e., both sides are Tails). She reaches into the bag and randomly pulls out a coin, with each coin being equally likely to be selected. Without looking at the coin she drew, she tosses it once.

What is the probability that the side of the coin that lands face-down is Heads?

2 The coin lands and shows Heads face-up. Given this information, what is the probability that the face-down side is also Heads?

3Alice discards the coin used in the first round. She knows that it showed Heads face-up but does not look at the other side of the coin. She reaches again into the bag and draws out a second coin from the 4 remaining coins, with each coin equally likely to be selected. Again, without looking at this second coin, she tosses it once. Given her knowledge of the result of the first coin toss (i.e., that it landed Heads face-up), what is the probability that this second coin toss results in Heads face-up?

**Answer this Question**

**Related Questions**

Probability - Alice has five coins in a bag: two coins are normal (i.e., fair ...

Probability - Two fair coins are flipped simultaneously. This is done repeatedly...

math - John has 2 coins, one fair and the other unbalanced so that the ...

maths - Suppose there are 10 coins laid out in front of you. All of the coins ...

Math - Four coins fall onto the floor. Find the probability that (a) exactly ...

math - Six fair coins are flipped, the probability that exactly three coins ...

Math - A game is played flipping three coins. If all three coins land heads up ...

statistics - Five coins all balanced the same were tossed 150 times. Note that, ...

Probability - Alice has two coins. The probability of Heads for the first coin ...

maths-urgent - a man has 3 unique coins such that the probability of obtaining a...