This problem involves the sum of the numbers showing on two fair dice.
(1) What is the probability that exactly one die shows a 3 given that the sum of the numbers is 9?
(2) What is the probability that the sum of the numbers is 9 given that at least one die shows a 3?
2006-09-29 16:21:59 · 6 answers · asked by J R 2 in Science & Mathematics ➔ Mathematics
1) 1/2
since the only possibilities that add to 9 are (3,6), (6,3), (4,5), (5,4), and half of them have exactly one 3.
2) 1/6
since there are 6 possibities for the other die and only one of them (6) will give a total of 9
2006-09-29 16:34:03 · answer #1 · answered by Joe C 3 · 0⤊ 0⤋
There are ways to make nine on two dice:
3 and 6
4 and 5
5 and 4
6 and 3
That's two ways to make 9 given one die has a 3 out of four possible ways to make 9. The odds are 1/2.
(2) If one die has a 3, there are six possibilities for the other die. Only one of those possibilities (6), makes the total nine. The probability is 1/6.
2006-09-29 23:29:57 · answer #2 · answered by Steve A 7 · 2⤊ 0⤋
3 times 3 is equal 9. ( 3x3= 9),2 dice showing same number.
2006-09-29 23:32:29 · answer #3 · answered by flowermieses@verizon.net 3 · 0⤊ 1⤋
both questions are asking the same thing there is only one possible combination to create a 9 with one being a 3 the other has to be a 6 therefore the probability is 1in 36. for both
2006-09-29 23:28:51 · answer #4 · answered by Joseph M 2 · 0⤊ 1⤋
you cannot solve this without telling us how many dice there are
2006-09-29 23:29:42 · answer #5 · answered by Gretchen B 3 · 0⤊ 1⤋
good ?
2006-09-29 23:43:00 · answer #6 · answered by Anonymous · 0⤊ 0⤋