Probability P(A or B)

Are events that cannot occur in the same trial at the same time.

P( not A)

*always simplify*

• 1/4

• 6/8

• 3/4

• 1

In a class with 20 students, 5 are in the drama club and 12 are in the yearbook club. , what is the probability that the selected student is in the yearbook club?

• 12/40

• 1/2

• 5/20

• 3/5

P (male/ SUV)

• 21/ 240

• 7/52

• 60/156

• 60/ 240

A survey found that 19% of the population owned dogs,14% owned cats and 6 % owned both a cat and a dog .Find the probability that a random person own a cat or a dog. What rule would you use ?

• P( A or B) = P ( A) + P( B) - P ( A and B)

• P( B/ A)

you flip a penny. what is P( tails)

• 25%

• 50%

• 1%

• 100%

the probability that event B occurs given that event A has already occurred. What type of probability is this?

• relative frequency

• Overlapping

• Conditional

Given that a passenger selected at random was a child find the probability that the passenger traveled in third class .

P ( Third class/ child)

• 109/ 706

• 79/ 709

• 79/109

True or false .In general P (A/ B ) = P(B/A) . you can reverse and the probability is the same either way .

• False

• True

in a cup are numbers 1- 20 what are the chances of picking an even number.

• 10/20

• 1/2

• 9/20