Amateur
What is the probability that you will get a sum of 8 when you throw three dice simultaneously?
Similarly, What is the probability that you will get a sum of 22 when you throw four dice simultaneously?
What is the probability that you will get a sum of 8 when you throw three dice simultaneously?This sum of 8 can occur in the following cases:
1-1-6 --> 3!/2!=3 ways;1-2-5 --> 3!=6 ways;
1-3-4 --> 3!=6 ways;
2-2-4 --> 3!/2!=3 ways;
2-3-3 --> 3!/2!=3 ways.
Total of 3+6+6+3+3=21 ways.
Now, since the total number of outcomes is 6^3, then the probability is 21/6^3.
What is the probability that you will get a sum of 22 when you throw four dice simultaneously?This sum of 22 can occur in the following cases:
6-6-6-4 --> 4!/3!=4 ways;
6-6-5-5 --> 4!/(2!2!)=6 ways.
Total of 4+6=10 ways.
Now, since the total number of outcomes is 6^4, then the probability is 10/6^4.
Hope it's clear.
Small point that needs clarification. Shouldn't 'simultaneously' mean that the dices aren't thrown in any particular order and therefore the order doesn't matter ?