Asked by Lucy
What is the probability of getting an even number on a single roll of a number cube if you roll a 3 or greater.
My answer: is 1/3 because there are only two numbers that are even and greater than 3 on the number cube.
Teacher marked this as wrong. How did I mess this one up?
My answer: is 1/3 because there are only two numbers that are even and greater than 3 on the number cube.
Teacher marked this as wrong. How did I mess this one up?
Answers
Answered by
Reiny
this sure looks like a "conditional" probability.
in general
P(A│B) = P(A AND B)/P(B)
read: P(A│B) as "the prob of A given B"
so let A be (even number)
let B be (greater or equal to 3)
so P(A and B) = 2/6 = 1/3
P(B) = 4/6 = 2/3
so P(A│B) = (1/3)/(2/3) = 1/2
in general
P(A│B) = P(A AND B)/P(B)
read: P(A│B) as "the prob of A given B"
so let A be (even number)
let B be (greater or equal to 3)
so P(A and B) = 2/6 = 1/3
P(B) = 4/6 = 2/3
so P(A│B) = (1/3)/(2/3) = 1/2
There are no AI answers yet. The ability to request AI answers is coming soon!
Submit Your Answer
We prioritize human answers over AI answers.
If you are human, and you can answer this question, please submit your answer.