Math 30-2

Unit 4: Probability

Lesson 4: Independent-Dependent Events

I need solutions for these questions please. their will be a answer key after the questions below that my teacher gave it to me. thank you

5.

Let A and B be events with P(A0=4/9 and P(B)=5/9, and P(A or B)=3/4.

Determine

a) P (A and B)

b) P (A \ B)

c) P (B \ A)

7. The probability the Neave will pass Grade 12 math and Grade 12 physics this semester is

0.94 and 0.81 respectively. If these events are independent, determine the probability (to

four decimal places that she will pass

a) both math and physics b) math but not physics

c) physics but not math d) neither math nor physics

8. Two cards are drawn without replacement from a standard deck of 52 cards.

a) both cards are diamonds b) both cards are eights c) neither card is black

d) the first card is a spade and the second card is a heart

e) one of the cards is black and the other is red

9. Students did a survey in our school. They found that 60% of the students wear jeans

almost daily, 55% of the students wear runners, and 20% neither wear jean nor runners.

a) Determine the probability that a randomly selected student will have jeans and runners.

b) State, with a reason, if these two characteristics are independent.

answer key

5. a) 1/4, b) 9/20, c) 9/16

7. a) 0.7614, b) 0.1786, c) 0.0486, d) 0.0114

8. a) 1/17, b) 1/221, c) 25/102, d) 13/204, e) 26/51

9. a) 0.35, b) Since P (J R ) P (J) P (R) , the two characteristics are not independent.