alleryStart learning →A fair die is rolled. Event A is an even face and event B is a face below four. Given that the face is below four, what is the chance it is even?
AOne in two
BOne in three
COne in six
DTwo in three
Answer & Solution
Correct answer: B. One in three
1. A conditional chance shrinks the sample space to the outcomes that meet the condition.
2. Faces below four are 1, 2 and 3, so there are three outcomes to consider.
3. Among those three, the even faces are just 2.
4. So one of the three remaining outcomes is even.
5. The chance is therefore one in three.
6. Answering one in six uses the full six-sided sample space and ignores the condition.
7. Answering one in two uses the share of even faces on the whole die, which the condition has already changed.
_Source: OpenStax High School Statistics (CC BY 4.0), Ch 2 "Descriptive Statistics" and Ch 3 "Probability Topics", section 3.1 Terminology_
Keep practising Probability Topics
Browse all Probability Topics questions for CBEST, or explore more Mathematics topics.
Related questions
Sort the draws by independenceMerge the coin chancesA bag holds four green, three red and two yellow marbles. Two are drawn without replacemenThree red and eight blue balls sit in an urn, and two are drawn with replacement. In how mAn urn holds 3 red and 8 blue balls. Two are drawn one at a time with replacement. How manIn a class, 60 percent are female and 50 percent have long hair. If those two facts were iCarlos scores each of two attempts with chance 0.65, and scores both with chance 0.585. WhCarlos scores on 65 percent of his shots, and is 90 percent likely to score his second giv