Aptitude - Probability - Discussion
Discussion Forum : Probability - General Questions (Q.No. 4)
4.
What is the probability of getting a sum 9 from two throws of a dice?
Answer: Option
Explanation:
In two throws of a dice, n(S) = (6 x 6) = 36.
Let E = event of getting a sum ={(3, 6), (4, 5), (5, 4), (6, 3)}.
 P(E) = |
n(E) | = | 4 | = | 1 | . |
| n(S) | 36 | 9 |
Discussion:
52 comments Page 2 of 6.
Amol Pawar said:
10 years ago
Dice has 6 faces, i.e (1, 2, 3, 4, 5, 6) in this addition of 9 occurs when (5+4 or 4+5) and (6+3 or 3+6) that means 4 ways.
In this way n(e) = 4 and n(s) = 6*6 =36.
P (e) = n(e)/n(s) = 4/36 = 1/9.
In this way n(e) = 4 and n(s) = 6*6 =36.
P (e) = n(e)/n(s) = 4/36 = 1/9.
Arif said:
7 years ago
At first you draw sample space then you find pair which sum is 9, (1,1), (1,2),....... (5,4), (6,3),(3,6), (4,5).
Total pair 36 and sum of 9 pair is 4 them p(sum 9)= 4 ÷ 36 = 1/9.
Total pair 36 and sum of 9 pair is 4 them p(sum 9)= 4 ÷ 36 = 1/9.
(4)
Ranjith said:
1 decade ago
I understood of this way I don't know this is right or wrong.
We want to getting some 36 = 36+9 = 45.
45+9 = 54.
54+9 = 63.
We want to getting some 36 = 36+9 = 45.
45+9 = 54.
54+9 = 63.
Deepthi said:
9 years ago
By throwing 2 dies, to get a sum of 9 there are also possibilities of getting (1,8) (2,7) (3,6) (4,5) (5,4) (6,3) (7,2) (8,1) we have 8 possibilities please explain this.
Swathi said:
7 years ago
Why we should not use the permutations here?like sum 9 can appear in either (6, 3) or (3, 6) , (5, 4) or (4, 5). Why we only choose the one possibility?
(1)
Laxmipriya said:
10 years ago
Why to do multiplication like 6*6=36? Why we can't do addition?
Like 6+6 = 12. I can't understand when to do addition and when to do multiplication.
Like 6+6 = 12. I can't understand when to do addition and when to do multiplication.
Syam said:
1 decade ago
{ (3, 6) , (4, 5) , (5, 4) , (6, 3) } is a case only.
We can get (6, 3) , (5, 4) , (3, 6) , (4, 5) also.
So answer is 8/38 = 2/9.
Am I correct ?
We can get (6, 3) , (5, 4) , (3, 6) , (4, 5) also.
So answer is 8/38 = 2/9.
Am I correct ?
Ajax said:
1 decade ago
Short method of find sum of two dice.
Sum - Time.
2 - 1.
3 - 2.
4 - 3.
5 - 4.
6 - 5.
7 - 6.
8 - 5.
9 - 4.
10 - 3.
11 - 2.
12 - 1.
Sum - Time.
2 - 1.
3 - 2.
4 - 3.
5 - 4.
6 - 5.
7 - 6.
8 - 5.
9 - 4.
10 - 3.
11 - 2.
12 - 1.
Pooja gm said:
7 years ago
Why we take this case only?
(3+6)
(4+5)
(5+4)
(6+3).
This also possible;
(7+2),
(1+8),
(2+7),
(8+1),
Please explain the reason.
(3+6)
(4+5)
(5+4)
(6+3).
This also possible;
(7+2),
(1+8),
(2+7),
(8+1),
Please explain the reason.
(1)
Joshua said:
7 years ago
Because in a throw of two dices there is only 6x6, is the last the number won't Or should not exceed 6.
(1)
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