Read the two statements and choose the correct option. I. (A B)' = A' B'. II. (A B)' = A' B'.

Question 21

MediumOriginal question

Read the two statements and choose the correct option.
I. $(A \cup B)' = A' \cap B'$ .
II. $(A \cap B)' = A' \cap B'$ .

Only ICorrect answerYour answerOnly IICorrect answerYour answerBoth I and IICorrect answerYour answerNeither I nor IICorrect answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer A

Correct answer: A

I: not 'A or B' means neither $A$ nor $B$ , that is $A' \cap B'$ . True.
II: not 'A and B' means at least one fails, which is $A' \cup B'$ , not $A' \cap B'$ . False.

Worth noting

Taking a complement turns $\cup$ into $\cap$ and $\cap$ into $\cup$ .

Ten questions from Probability, at your own pace.