Question

The probability that it is Friday and that a student is absent is 0.03. Since there are five school days in a week, the probability that it is Friday is 0.2. What is the probability that a student is absent given that today is Friday?

Answer 1

0.15

Explanation:

We have been given that the probability that it is Friday and that a student is absent is 0.03. Since there are five school days in a week, the probability that it is Friday is 0.2.

To solve the given problem, we will use conditional probability formula.

`P(B|A)=\frac{P(A\text{ and }B)}{P(A)}`, where,

P(B|A) = Probability of event B given A.

P(A and B) = Probability of event A and B.

P(A) = Probability of event A.

`P(\text{Absent}|\text{Friday})=\frac{P(\text{Friday and absent})}{P(\text{Friday})}`

`P(\text{Absent}|\text{Friday})=(0.03)/(0.2)`

`P(\text{Absent}|\text{Friday})=(3)/(20)`

`P(\text{Absent}|\text{Friday})=0.15`

Therefore, the probability, that a student is absent given that today is Friday, would be 0.15.