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 5 of 6.
Kanchi said:
1 decade ago
s is a sample space i.e all possible outcomes
if two coins are tossed then s={HH,TT,HT,TH}
same in this qu. two dice -use then no of possible outcome
s={(1,1),(1,2),(1,3),(1,4),(1,5),(1,6)},
{(2,1),(2,2),(2,3),(2,4),(2,5),(2,6)}
..........
{(6,1),(6,2),(6,3),(6,4),(6,5),(6,5)}
n(s)=6+6+6+6+6+6=36
or
6*6=36
if two coins are tossed then s={HH,TT,HT,TH}
same in this qu. two dice -use then no of possible outcome
s={(1,1),(1,2),(1,3),(1,4),(1,5),(1,6)},
{(2,1),(2,2),(2,3),(2,4),(2,5),(2,6)}
..........
{(6,1),(6,2),(6,3),(6,4),(6,5),(6,5)}
n(s)=6+6+6+6+6+6=36
or
6*6=36
Anurag said:
1 decade ago
Ankita:.
Because 6c1 * 6c1 is 36.
Because 6c1 * 6c1 is 36.
Ankita said:
1 decade ago
How do we know that we have to pick up 6 * 6?
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 ?
Harikannan said:
1 decade ago
How to find event that is (3, 4) (4, 5) (5, 4) (6, 3) please explain.
Sreejith said:
1 decade ago
@Azam
In both throughs, it can be any of 1,2,3...,6(6C1 ways of selection). So total number of outcomes = 6C1*6C1 = 36
More clearly, the elements of sample spaces are
{(1,1),(1,2),(1,3),....,(2,1),(2,2),.....(6,1),(6,2),....(6,6)}
Hope you got it.
In both throughs, it can be any of 1,2,3...,6(6C1 ways of selection). So total number of outcomes = 6C1*6C1 = 36
More clearly, the elements of sample spaces are
{(1,1),(1,2),(1,3),....,(2,1),(2,2),.....(6,1),(6,2),....(6,6)}
Hope you got it.
Srinivas said:
1 decade ago
n(s)=36
n(a)=[36][45][63][54]
p(a)=4/36=1/9
n(a)=[36][45][63][54]
p(a)=4/36=1/9
Krish said:
1 decade ago
How it could be n(s)= (6 x 6)
AZAM said:
1 decade ago
In two throws of a dice, n(S) = (6 x 6) = 36.
HOW IT DO
PLEASE EXPLAIN
HOW IT DO
PLEASE EXPLAIN
VIAN said:
1 decade ago
@rama.
That is because the event of finding the sum 9 is 4.
That is because the event of finding the sum 9 is 4.
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