A driving exam consists of 30 multiple-choice questions. Each of the 30 answers is either right or wrong. Suppose the probability that a student makes fewer than 6 mistakes on the exam is 0.28 and that the probability that a student makes from 6 to 20 (inclusive) mistakes is 0.53. Find the probability of each of the following outcomes. a. A student makes more than 20 mistakes b. A student makes 6 or more mistakes c. A student makes at most 20 mistakes d. Which two of these three events are complementary?

a. P(x>20)=0.19

b. P(x≥6)=0.72

c. P(x≤20)=0.81

d. A and C

Step-by-step explanation:

We know that:

1) the probability that a student makes fewer than 6 mistakes is 0.28

2) The probaiblity that a student makes between 6 to 20 mistakes is 0.53.

We will express the proabilibities in function of the information we have.

a. Probability that a student makes more than 20 mistakes.

b. Probability that the student make 6 or more mistakes

c. Probability that a student makes 20 mistakes at most

d. A and C, because A takes a event of more than 20 mistakes and C takes the event of 20 or less mistakes. Both events cover a probability of 1.