draw a grid (matrix) of the 2 dice,
RED across the top
GREEN along the column
You will that for 6 of them , they are equal, e.g. 3,3
For 15 of them the green is more
fro 15 of them the red is more , (6+15+15=36)
so prob(red>green) = 15/36 = 5/12
from your chart, count how many have a sum < 10
easy way: count those 10 or more:
6,6 ; 6,5 ; 6,4 ; 5,6 ; 4,6 ; 5,5
i count 6, check that. Did I list all of them?
So less than 10 = 36-6 = 30
prob(less than 10) = (36-6)/36 = 5/6
do the rest of the problems with the help of your chart
A red die and a green die have been rolled. (6 sided) What is the probability of the event?
1.The number on the red die is greater than the number on the green die (Answer is 5/12 but how?)
2. The sum is less than 10.
3. The sum is even.
4. The sum is prime.
5. The sum is 7 or 11.
1 answer
1 answer