Pre-Cal 40S Slides May 25, 2007

The probability that Tony will move to Winnipeg is 2/9, and the probability that he will marry Angelina if he moves to Winnipeg is 9/20. The probability that he will marry Angelina if he does not move to Winnipeg is 1/20. Draw a tree diagram to show all outcomes.

1. What is the probability that Tony will move to Winnipeg and marry Angelina?

To be continued ...

The probability that Tony will move to Winnipeg is 2/9, and the probability that he will marry Angelina if he moves to Winnipeg is 9/20. The probability that he will marry Angelina if he does not move to Winnipeg is 1/20. Draw a tree diagram to show all outcomes.

2. What is the probability that Tony does not move to Winnipeg but does marry Angelina?

The probability that Tony will move to Winnipeg is 2/9, and the probability that he will marry Angelina if he moves to Winnipeg is 9/20. The probability that he will marry Angelina if he does not move to Winnipeg is 1/20. Draw a tree diagram to show all outcomes.

3. What is the probability that Tony does not move to Winnipeg and does not marry Angelina?

One card is drawn at random from a deck of 52 cards. What is the probability of drawing an ace or a diamond?

In a Pre-Cal 40S class of 25 students, seven students say they like Dr. Pepper, 11 students like Diet Dr. Pepper, and 3 like both. What is the probability that a student will not like either Dr. Pepper or Diet Dr. Pepper?

A rack contains 15 dresses. Five of the dresses are blue, six are green, and 4 are yellow. If selling each of the dresses is equally likely, what is the probability that if six dresses are sold, exactly two will be green?

In a car lot, 25% of the inventory are SUV’s, and 75% are passenger cars. 80% of the SUV’s, and 65% of the passenger cars, have air conditioning. What is the probability that a chosen vehicle will be an SUV given the vehicle has air conditioning?

A box of eight razor blades contains two defective blades. If two blades are drawn at random, with the first not replaced, what is the probability that exactly one of the two blades will be defective?

(a) How many different 4 digit numbers are there in which all the digits are different?

(b) If one of these numbers is randomly selected, what is the probability it is odd?

(c) What is the probability it is divisable by 5?

Mixed Practice ...

The probability of hitting a target when throwing a dart is 5/7. If 6 darts are thrown, what is the probability of exactly 4 hits?

If a biased coin is tossed 6 times, what is the probability of obtaining exactly 3 heads if the probability of getting heads on any one toss is 2/5?

There are 10 tickets in a hat, numbered from 1 to 10. If two tickets are drawn, what is the probability that the sum of the numbers on the tickets will be odd?

A shootout consists of teams A and B taking alternate shots on goal. The first team to score wins. Team A has a probability of 0.3 of scoring with any one shot. Team B has a probability of 0.4 of scoring with any one shot. If Team A shoots first, what is the probability of Team A winning on its third shot?

In room 1 there are 12 boys and 8 girls. In room 2 there are 7 boys and 9 girls. If a student is selected at random from one of the rooms, what is the probability that the student is a girl?

It is known that 10% of a population has a certain disease. A blood test for the disease gives a correct diagnosis 95% of the time. The test is equally reliable for persons with or without the disease. What is the probability that a person whose blood test shows positive for the disease actually has the disease?