Nine cards are numbered 1-9. what is the probability of drawing a number greater than 6 or an odd number.

I know the answer is 2/3 but I don't know how you find the probability when it says "greather than 6 OR and odd number"... how do you calculate the OR?

You can rewrite this such that the "OR" applies to mutually exclusive possibilities, and then you can add up the proababilities.

The probabilitity of drawing an odd number or a number larger than 6, is the same as drawing one of the odd numbers smaller than 6, or a number larger than 6. The OR now refers to mutually exclusive possibilitities and you can then add up the probabilities for them as there is no double counting.

Clearly there are 6 numbers that satisfy the criterium, so the probablity is 6/9 = 2/3.

YOu can also handle "OR" diurectly using the principle of exclusion and inclusion using the formula:

N[A OR B] = N[A] + N[B] - N [A AND B]

There are 3 numbers larger than 6, there are 5 odd numbers and there are 2 numbers that are larger than 6 nd odd. There are thus 3 + 5 - 2 = 6 numbers that are larger than 6 or odd.

To find the probability of a combination of events connected by the word "or," you need to calculate the individual probabilities of each event and then add them together, making sure not to count any overlapping cases twice.

In this case, you have two events: drawing a number greater than 6 and drawing an odd number.

1. Probability of drawing a number greater than 6:
Out of the nine cards numbered 1-9, there are only three numbers greater than 6 (7, 8, and 9). So, the probability of drawing a number greater than 6 is 3/9.

2. Probability of drawing an odd number:
Out of the nine cards, there are five odd numbers (1, 3, 5, 7, and 9). Therefore, the probability of drawing an odd number is 5/9.

Now, we need to add these probabilities together, but we need to make sure we don't count the overlapping cases (the numbers that are both greater than 6 and odd) twice.

Out of the three numbers greater than 6, only one (7) is odd. So, we subtract this overlapping case from the sum of the individual probabilities.

Probability of drawing a number greater than 6 or an odd number = P(greater than 6) + P(odd number) - P(greater than 6 and odd)
= 3/9 + 5/9 - 1/9
= 7/9

Therefore, the probability of drawing a number greater than 6 or an odd number is 7/9, not 2/3. Please check your answer again.

To find the probability of multiple events connected by "OR," you can use the following formula:

P(A or B) = P(A) + P(B) - P(A and B)

In this case, we are looking for the probability of drawing a number greater than 6 or drawing an odd number. Let's break it down:

Step 1: Find the probability of drawing a number greater than 6.
Out of the 9 cards, there are 3 numbers greater than 6: 7, 8, and 9. So the probability of drawing a number greater than 6 is 3/9.

Step 2: Find the probability of drawing an odd number.
Out of the 9 cards, there are 5 odd numbers: 1, 3, 5, 7, and 9. So the probability of drawing an odd number is 5/9.

Step 3: Find the probability of both events happening (drawing a number greater than 6 and an odd number).

Since there is only one card that satisfies both conditions (7), the probability of both events happening is 1/9.

Now, we can use the formula mentioned earlier:

P(greater than 6 or odd) = P(greater than 6) + P(odd) - P(greater than 6 and odd)
= 3/9 + 5/9 - 1/9
= 8/9 - 1/9
= 7/9

Therefore, the probability of drawing a number greater than 6 or an odd number is 7/9.