Question Math?
2016-06-10 5:21 am
Maria rolled a die 3 times. What is the probability that the sum of the 3 rolls is less than or equal to 5?
回答 (2)
2016-06-10 5:27 am
To rolled a die 3 times, No. of combinations = 6 × 6 × 6 = 216
To get a sum of the 3 rolls less than or equal to 5, the outcome could be :
(1, 1, 1)
(1, 1, 2), (1, 2, 1), (2, 1, 1)
(1, 2, 2), (2, 1, 2), (2, 2, 1)
(1, 1, 3), (1, 3, 1), (3, 1, 1)
P(the sum of the 3 rolls is less than or equal to 5)
= 10/216
= 5/108
To get a sum of the 3 rolls less than or equal to 5, the outcome could be :
(1, 1, 1)
(1, 1, 2), (1, 2, 1), (2, 1, 1)
(1, 2, 2), (2, 1, 2), (2, 2, 1)
(1, 1, 3), (1, 3, 1), (3, 1, 1)
P(the sum of the 3 rolls is less than or equal to 5)
= 10/216
= 5/108
2016-06-10 9:31 am
When a dice is rolled 3 times, No. of outcomes = 6 × 6 × 6 = 216
Sum of the 3 rolls less than or equal to 5,could be
Sum =3 (1, 1, 1) total 1
Sum =4 (1, 1, 2), (1, 2, 1), (2, 1, 1) total 3
Sum =5 (1, 2, 2), (2, 1, 2), (2, 2, 1) ,(1, 1, 3), (1, 3, 1), (3, 1, 1) total 6
Total cases of sum less than or equal to 5=10
P(the sum of the 3 rolls is less than or equal to 5)
= 10/216
= 5/108
Sum of the 3 rolls less than or equal to 5,could be
Sum =3 (1, 1, 1) total 1
Sum =4 (1, 1, 2), (1, 2, 1), (2, 1, 1) total 3
Sum =5 (1, 2, 2), (2, 1, 2), (2, 2, 1) ,(1, 1, 3), (1, 3, 1), (3, 1, 1) total 6
Total cases of sum less than or equal to 5=10
P(the sum of the 3 rolls is less than or equal to 5)
= 10/216
= 5/108
收錄日期: 2021-04-18 14:56:53
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