Probability: A and B
How to find the probability P(A and B): 1 example and its solution.
Example
Solution
Solution (Detail)
Set A as
picking an odd number from 1 to 10.
{1, 3, 5, 7, 9}
Set B as
picking a prime number from 1 to 10.
{2, 3, 5, 7}
Then [A and B] is,
write the numbers in both A and B,
{3, 5, 7}.
The number of {3, 5, 7} is 3.
n(A and B) = 3
The number of [1 ~ 10] is 10.
n(S) = 10
Then P(A and B) = 3/10.
Probability
So 3/10 is the answer.