Question

2. (08.03) A teacher gave her class two exams; 60% of the class passed the second exam, but only 48% of the class passed both exams. What percent of those who passed the second exam also passed the first exam? (2 points) 80% 12% 30% 48%

Answer 1

Only 80% students passed the second exam and also passed the first exam .

Conditional probability is used to find the probability of an event A given that event B has already occurred.

It is denoted by P(A/B)=P(A∩B)/P(B)  .

In the given question

Let A be the event for students passed in first exam.

Let B be the event for students passed in second exam.

Given

Only 48% passed in both the exam that means

P(A∩B)=48%=0.48   ...(i)

and

60% students passed the second exam , that is

P(B)=60%=0.60       ...(ii)

To find the probability of students passed in second exam given that they passed in first exam , conditional probability is used that is P(A/B), denoted by

P(A/B)=P(A∩B)/P(B)

Substituting the values from equation (i) and (ii) we get

P(A/B) = 0.48/0.60

=48/60

Converting 48/60 to percent

=48/60*100

=80%

Therefore , Only 80% students passed the second exam and also passed the first exam , the correct option is 80%.

Learn more about Conditional Probability here

https://brainly.com/question/11899923

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