Two dice are rolled. Find the probability that the sum of the numbers on the two dice is 4.

Question

Two dice are rolled.  Find the probability that the sum of the numbers on the two dice is 4.

sonyalee77 · Answer

@Directrix

directrix · Answer

There are 6 possible outcomes for the first die and 6 outcomes for the second die. (Die is the singular of dice.) By the Fundamental Principle of Counting, that gives 6*6 = 36 possibilities of outcomes for the pair of dice.

directrix · Answer

Your task is to look at the attached chart above and count the number of throws that have spots that sum to 4.

So , do that now and then we will get the probability.

directrix · Answer

@Sonyalee77   How many sums of 4 did you count? Let's knock out this problem.

sonyalee77 · Answer

12

directrix · Answer

Would you write down the first six of them, please?

sonyalee77 · Answer

IM SO CONFUSED

directrix · Answer

Look on the attached chart. There are only three ways to get a sum of four.

sonyalee77 · Answer

OH I just counted all of the pairs with 4 in it

directrix · Answer

So when you got 12 sums of 4, I think you just looked for a four and counted it. 
That is not what we are doing. We are looking for sums of four.

So, if you counted (4,4) then that is a 4 on one die  and another 4 on the other. That adds to 8. We don't want that. We want a sum of four.

directrix · Answer

So, the probability of a 4 on a single toss of a pair of cubical dice is 3/36 which is 1/12.

P(sum of 3) = 3/36 = 1/12.

sonyalee77 · Answer

OOOOOOOHHHH Thank you so much