Part A: Philip asks Julia to pick a number at random from 1 to 100, and then asks Shelly to do the same . What is the probability that both girls will select 49?

Question

Part B: In a game, William and Mary take turns choosing cards at random from a bag. Each card shows a “W” or “M”. A player chooses a card, records the letter, and puts the card in a discard pile.

Are the letters drawn independent or dependent events? Explain

Part C: Suppose there are three blue marbles and three yellow marbles in a bag and you want to remove two marbles. What is the probability that you will select a blue marble and then a yellow marble? Express your answer as a percent. Show your work.

Answer 1

Part A:

Probability of both choosing 49 = (1/100) x (1/100) = 1/10,000

Part B:

These as dependent events because the first person's draw (either William or Mary) changes the probability of what the second person will draw. The total number of cards in the bag is reduced by 1, and, either the W or M card will be reduced by 1.

Part C:

Probability of first marble being blue and second marble being yellow is:

(3/6) x (3/5) = 3/10.

Expressed as a percentage = 30%

Answer 2

A: (1/100) x(1/100) = 1/10000 or 0.01%

probability of the first girl picking "49" is 1/100 since it is one of the 100 numbers available and it is the same for the second girl. The two events are independent, so you just multiply those probabilities.

B; They are dependent, since it depends on the cards previously chosen.

C: There are 3 blue and 3 yellow marbles for the first draw and then 2 blue and 3 yellow marbles for the second draw. That means 3 (blue) out of 6 total for the first draw and 3 (yellow) out of 5 total for the second draw.

(3/6 )x(3/5)=(1/2)x(3/5)=3/10=30/100 or 30%