Emily is playing a board game that has a spinner divided into equal sections numbered 1 to 18. The probability of the spinner landing on an even number or a multiple of 3 ?
1 Answer
Explanation:
We want to find the probability of landing on an even number or a multiple of 3, so we should use the addition rule for the union of two events:
Let's make
- A = the probability of landing on an even number, and
- B = the probability of landing on a multiple of 3
What is P(A) (the probability of landing on an even number? 2, 4, 6, 8, 10, 12, 14, 16, and 18 are all even, so P(A) is
What is P(B) (the probability of landing on a multiple of 3? 3, 6, 9, 12, 15, and 18 are multiples of 3, so P(B) is
What is P(A and B) (the probability of landing on an even number that's also a multiple of 3)? 6, 12, and 18 are all even AND multiples of 3. So P(A and B) is
Now we can plug our values into the equation!