What combination of numbers are needed in order to get a sum of 9?
It can be:
• First die is 6 , second die is 3
• First die is 3 , second die is 6
• First die is 4 , second die is 5
• First die is 5 , second die is 4
How many possible combinations are made? Yep, 4 possible combinations.
Recall the formula for probability
[tex]Probability = \frac{Number of desired outcomes}{Number of all possible outcomes} [/tex]
There are 4 desired number of outcomes.
How about the total possible outcomes?
• How many numbers are possible to appear when the first die is rolled?
Answer: 6
• What about the second die?
Answer: Also 6
• Therefore, total possible outcomes = 6 * 6 = 36 outcomes
You can now solve for the probability.
[tex]Probability = \frac{4}{36} = \frac{1}{9} [/tex] or approximately 11.11%
