Amy's Probability Post (E-50; Questions N-P)

N) If you flip a coin 150 times, about how many times would you expect to get heads?

The answer will be 75, 1/2 or 50% because there are 2 sides on a coin. If you divide 150 by 2, the answer will be 75. 75 is a way of showing that it is the half of 150. You can get a 50/50 chance of getting heads when you flip the coin. Half of the chance will land on heads and the other half of the chance will land on tails. 1/2 is a way of writing one half of the chance of flipping a heads. Another way of showing it is 50%. 50% is half of the chance out of 100% when you can flip the coin and half the chance will be heads.

K) If you randomly pick a date in April, how many equally likely outcomes are there?

There would be 30 outcomes because there are 30 days in April. If you randomly pick a date in April, there would be 30 days for you to pick. So there are 30 days or 30 total possible outcomes if you randomly pick a date in April.

C) The letters a, e, i, o, u, and y are vowels. If one letter of the alphabet is chosen at random, what is the probability it is a vowel?

The probability of it is a vowel is 6/26=3/13 or 23% because there are 26 total possible outcomes and 6 possible outcomes. 6 is how many letters that are vowels in the alphabet and 26 is the total of letters in the alphabet. 23% is the percent of how many letters that are vowels out of 100%.

P) A magician asks you to pick a card, any card, from a standard deck of 52 cards. What is the probability of picking an ace?

The answer will be 4/52=1/13 or 7.6%. 4 is the possible outcomes which is the number of how many aces are in the deck of cards, 52 is the total possible outcomes and it is the total number of how many cards are specifically in the deck of cards. When you reduce 4/52, you get 1/13. It can be written in both ways. Another way that it can be written is that when you divide 4 by 52 and multiply it by 100, you will get the answer of 7.6%. 7.6% means that you will get 7.6% of a chance of picking an ace in the deck of cards.

My question: A magician asks you to pick a card, any card, from a standard deck of 52 cards. What is the probability of picking a 2 and queen?

The answer will be 8/52=4/26=2/13 or 15.3%. This time 8 is the possible outcome and 52 is still the total possible outcome. The 4 changed into the 8 because according to the deck of 52 cards, there are 4 cards for each number. So this means queen and the 2 have 4 cards for that number. You will have a chance of 4/26 to pick a queen or 2 out of the deck of cards. When you reduce 8/52, you will get 4/26. 15.3% means that you will get 15.3% of a chance of picking a 2 or a queen.