Probability Key

You are given a standard deck of 52 playing cards, which consists of 4 suits: diamonds, hearts, clubs, and spades. Each suit has 13 cards as follows: ace, deuce, trey, four, five, six, seven, eight, nine, ten, jack, queen, and king. The jacks, queens and kings are picture cards. There are no joker cards in a standard deck. There is four of a kind,

one in each suit.

The First Law of Probability : the results of the first trial of a chance event do not

affect the results of later trials of the same event. In other words,

no matter how many times a flipped coin lands on tails,

every flip still has a ½ chance of tails.

What is the probability of picking a spade from a full deck

of cards?

52 playing cards4 suits

13 cards in each suit

What is the probability of picking a spade from a full deck of cards?

13/52 = .25 = 25%

52 playing cards4 suits

13 cards in each suit

What is the probability of picking an ace from a full deck of cards?

52 playing cards4 suits

13 cards in each suit

What is the probability of picking an ace from a full deck of cards?

4/52 = .076

52 playing cards4 suits

13 cards in each suit

What is the probability of picking a card with a face value less than five?

52 playing cards4 suits

13 cards in each suit

16/52 = .31 = 31%

52 playing cards4 suits

13 cards in each suit

What is the probability of picking a card with a face value less than five?

52 playing cards4 suits

13 cards in each suitjacks, queens and kings are picture cards

What is the probability of picking a picture card?

52 playing cards4 suits

13 cards in each suitjacks, queens and kings are picture cards

What is the probability of picking a picture card?

12/52 = .23 = 23%

What is the probability of a family having a baby boy?

What is the probability of a family having a baby boy?

1/2 = .50 = 50%

What is the probability of a family

having a second baby boy?

What is the probability of a family

having a second baby boy?

1/2 = .50 = 50%

. What is the probability of rolling a six when one die is rolled?

. What is the probability of rolling a six when one die is rolled?

1/6 = .17 = 17%

What is the probability of rolling a sum of 9 when two dice are

rolled?

What is the probability of rolling a sum of 9 when two dice are

rolled?

4/12 = 1/3 = .33 = 33%

Second Law of Probability: The probability of two or more

independent events occurring together is the product of

their separate probabilities. In other words, if there is a 50%

(1/2) chance of a couple having one boy,

there is a 1/2X1/2X1/2X1/2 chance or 1/16 chance of a couple having 4

boys.

Second Law of Probability: The probability of two or more independent events occurring together is the product of their separate

probabilities.

What is the probability of obtaining two fours in the random tossing of

a pair of dice?

Second Law of Probability: The probability of two or more independent events occurring together is the product of their separate

probabilities.

What is the probability of obtaining two fours in the random tossing of

a pair of dice?1/6 x 1/6 = 1/36 = .028 = 2.8%

Second Law of Probability: The probability of two or more independent events occurring together is the product of their separate

probabilities.

What is the probability of obtaining a six and a three in the random

tossing of a pair of dice?

Second Law of Probability: The probability of two or more independent events occurring together is the product of their separate

probabilities.

What is the probability of obtaining a six and a three in the random

tossing of a pair of dice? 1/6 x 1/6 = 1/36 = .028 = 2.8%

What is the probability of winning the Texas lottery?

What is the probability of winning the Texas lottery?

1/50 x 1/49 x 1/48 x 1/47 x 1/46 x 1/45 …..According to Ask Jeeves:

The number of combinations of 6 items taken from a pool of 50 is:15,890,700

Only 1 of these will be the winning combination, So you have 1 chance in

15,890,700 of winning with a single lottery ticket. Therefore,

the probability is 1/15,890,700 or about 0.000000063.

What is the probability that two fraternal twins

( twins resulting from two eggs and two sperm) will both be

girls?

What is the probability that two fraternal twins

( twins resulting from two eggs and two sperm) will both be

girls?

1/2 x 1/2 = 1/4 = .25 = 25%

What is the probability that two identical twins will both be

girls?

What is the probability that two identical twins(twins resulting from one egg and one sperm) will

both be girls?

1/1 x 1/1= 1/1 = 1 = 100%

What is the probability that two identical twins

will consist of one boy and one girl?

What is the probability that two identical twins

will consist of one boy and one girl?

0/1 x 0/1 = 0 = 0%

Third Law of Probability: The probability that either of

two mutually exclusive events will occur

is the sum of their separate probabilities.

What is the probability of rolling a one or a two in a single toss of a

die? How many sides to a die?

Third Law of Probability: The probability that either of

two mutually exclusive events will occur

is the sum of their separate probabilities.

What is the probability of rolling a one or a two in a single toss of a

die? One die has six sides.

1/6 + 1/6 = 2/6 = 1/3 = .33 = 33%

Third Law of Probability: The probability that either of

two mutually exclusive events will occur

is the sum of their separate probabilities.

What is the probability of rolling a total of two

or a total of twelve with a pair of dice?

Third Law of Probability: The probability that either of

two mutually exclusive events will occur

is the sum of their separate probabilities.

What is the probability of rolling a total of two

or a total of twelve with a pair of dice?

1/6 x 1/6 = 1/36 + 1/6 x 1/6 = 1/36.056 = 5.6 %

Third Law of Probability: The probability that either of

two mutually exclusive events will occur

is the sum of their separate probabilities.