Suppose you ask a friend to randomly choose an integer between 1 and 10, inclusive.
What is the probability that the number will be more than 5 or odd? (Enter your probability as a fraction.)
First, we need to find the probability that the chosen number is more than 5. That would be the numbers 6, 7, 8, 9, and 10 out of the total of 10 numbers, so the probability is 5/10 or 1/2.
Next, we need to find the probability that the chosen number is odd. That would be the numbers 1, 3, 5, 7, and 9 out of the total of 10 numbers, so the probability is 5/10 or 1/2.
Since the numbers above 5 and the odd numbers overlap with the numbers 7 and 9, we have counted those numbers twice. So, we need to subtract the probability of choosing 7 and 9 (1/10 + 1/10) once.
Therefore, the probability of the number being more than 5 or odd is:
1/2 + 1/2 - 1/10 - 1/10 = 4/5
So, the probability is 4/5.