Section 4.4 Multiplication rule
In this section, the event
A and B
( A occurs in the first trial )
( B occurs in the second trial )
Suppose there are two questions in an exam:
(true or false) Abraham Lincoln was the president during Civil War.
(check the correct answer)
5 + 7 =
Suppose someone guesses both answers. What is the probability that both are correct?
Let us do it hard way: Write the sample space:
There is only one way both answers are correct, i.e., (T,c)
P( both answers are correct )
1 / 10