Question

There is a 60% chance that your math teacher will give a pop quiz tonight, and due to the fact that you have a soccer game, there is a 85% chance you will not be able to do your math homework.

You decide that you will not do the homework if the probability of there being a pop quiz and your not doing the homework is greater than 80%.


What is the probability of there being a pop quiz and your not doing your homework?

A) 0.06

B) 0.09

C) 0.34

D) 0.51

Answer 1

D) 0.51, and do the homework

Explanation:

First, we have the event "Probability of give a pop quiz" and event 2 "Probability of not doing homework".

The soccer game, and the pop quiz are not related, which means that the outcome of one or another event, will not affect the fact of the soccer game to be realized, so these 2 previous events are independent events, you can either have the quiz and not doing the homework, or even not have the quiz but still do the homework, the result of one will not affect the outcome of the other, hence:

P(A∩B) = P(A) * P(B)

Replacing the data we have:

P(A∩B) = 0.6 * 0.85

P(A∩B) = 0.51 or 51%

This result is lower than 80%, therefore, you'll do the homework