Question

We perform the experiment "toss two dice." What is the probability of the event, "The sum of the faces equals 5"?
Answer

a) 4/36

b) 1/36

c) 1/6

d) 1/9

Answer 1

The sample space has 36 possible combinations of numbers. These can be set out in column form as follows:
6,6 5,6 4,6 3,6 2,6 1,6
6,5 5,5 4,5 3,5 2,5 1,5
6,4 5,4 4,4 3,4 2,4 1,4
6,3 5,3 4,3 3,3 2,3 1,3
6,2 5,2 4,2 3,2 2,2 1,2
6,1 5,1 4,1 3,1 2,1 1,1

Now you need to count the number of combinations where the sum is 5. Then divide that number by 36 to find the required probability.

Answer 2

is the final answer 1/9?

Answer 3

Did you count the number of combinations where the sum is 5?

Answer 4

Well, if you look at the top left hand pair of numbers which are 6, 6, you can see that
6 + 6 does not equal 5. However if you look at the bottom pair of numbers in the third column from the left, which are 4, 1, you can see that 4 + 1 = 5. therefore there is one pair of numbers in the third column that adds up to 5.

Answer 5

oh ok! i understand now. thank you!

Answer 6

is the final answer 4/36?

Answer 7

4/36 is correct. However 1/9 is the simplification of 4/36.