Math 30-2

Unit 4: Probability

Lesson 3: Mutually Exclusive Events

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

4. McKenzie and Alicia are two runners in a race. The probability that McKenzie wins the

race is 1/8

and the probability that Alicia wins the race is 2/9. Calculate the probability thatMcKenzie or Alicia wins the race.

5. In a group of Westwood students, the probability that a student chosen at random rides the bus to school is 0.73 and the probability that a student has brown hair is 0.8. If the

probability that a student has brown hair or rides a bus to school is 0.56, calculate the

probability that a student has brown hair and rides the bus to school.

6. Ronan si playing with an incomplete deck of cards. When one card is selected at random

from the incomplete deck, the probability that it is a club is 0.2 and the probability that is is

a face card is 0.3. If the probability that the card is a club and a face card is 0.25, calculate

the probability that the card is a club or a face card.

8. Mariam and Horizon have had problems with their cell phones in the last while. They

phones have not been recording every night so they wake up in the morning at times and

their phones are dead. They decided to record the number of times each phone is charged

during one month. Every morning for thirty days they recorded the following information.

Mariam's phone was charged 20 times.

Horizon's phone was charged 18 times.

Both phones were charged 40% of the time.

What is the probability that on any particular morning during the month

a) at least one of the phones was charged? b) they cannot use either of the two phones?

Answer key

4. 25/72

5. 0.97

6. 0.35

8. a) 13/15, b) 2/15