Question

Exercise 2

Answer 1

Answer:

a) 0.72

b) 0.98

Step-by-step explanation:

We are given the following information in the question:

P(passing maths exam) = P(m) = 0.9

P(passing Spanish exam) = P(s) = 0.8

It is assumed that the results of the two exams are independent of each other.

a) probability that she passes both exams

By assumption of independence, we can write:

$P(\text{passes both exam} = P(M\cap S) \\=P(M)\times P(S) = 0.8\times 0.9 = 0.72$

0.72 is the probability that Josie will pass both the exams.

b) probability that Josie passes at least one of the exam

$P(\text{at least one of the exams}) = P(M\cup S)\\= P(M) + P(S) - P(M\cap S)\\= 0.9 + 0.8 - 0.72 = 0.98$

0.88 is the probability that Josie passes at least one of the exams.