Aptitude - Probability - Discussion
Discussion Forum : Probability - General Questions (Q.No. 10)
10.
Two dice are tossed. The probability that the total score is a prime number is:
Answer: Option
Explanation:
Clearly, n(S) = (6 x 6) = 36.
Let E = Event that the sum is a prime number.
| Then E | = { (1, 1), (1, 2), (1, 4), (1, 6), (2, 1), (2, 3), (2, 5), (3, 2), (3, 4), (4, 1), (4, 3), (5, 2), (5, 6), (6, 1), (6, 5) } |
n(E) = 15.
| P(E) = |
n(E) | = | 15 | = | 5 | . |
| n(S) | 36 | 12 |
Discussion:
64 comments Page 2 of 7.
DEBAI said:
1 decade ago
Hi RAM, if you tossed 2 dice then you get total 6x6 ie 36 possible cases (equallay likely cases) the above mentioned 15points are prime nos (2, 3, 5, 7, 11, 13, 17, 19. ) if you add any one out of 15 get prime no. That's all.
Lionel said:
9 years ago
Assume that two independent random samples of size 100 each is taken from a population that has a variance of 36. What is the probability that the difference in the sample means is more than 2?
Please give me the solution.
Please give me the solution.
Osei james said:
9 years ago
If two numbers are selected at random, one after the other with replacement from the set A = (5, 6, 7, 8, 9). Find the probability of selecting at least one prime number.
Can anyone help me to solve this problem.
Can anyone help me to solve this problem.
Suvendu said:
1 decade ago
As the question says sum should be a prime number.
So sum must be 2, 3, 5, 7, 11,
So probability should be (1, 1) (1, 2) (2, 1) (1, 4) (4, 1) (3, 4) (4, 3) (5, 6) (6, 5).
So probability= (9/36) =1/4.
So sum must be 2, 3, 5, 7, 11,
So probability should be (1, 1) (1, 2) (2, 1) (1, 4) (4, 1) (3, 4) (4, 3) (5, 6) (6, 5).
So probability= (9/36) =1/4.
Priya said:
5 years ago
@All.
Why here we perform addition operation to get a Prime number? Instead of getting total as prime we use (product or subtract).
Why only addition is performed? Can anybody explain this clearly!
Why here we perform addition operation to get a Prime number? Instead of getting total as prime we use (product or subtract).
Why only addition is performed? Can anybody explain this clearly!
Tuhin said:
1 decade ago
We have prime numbers between 2 To 12 as 2,3,5,7,11.
There is 1 Way to get sum as 2, 2 ways to get sum 3, 4 To get 5, 6 Ways to get 7 And 2 Ways to get 11. So total of 15, therefore prob = 15/36.
There is 1 Way to get sum as 2, 2 ways to get sum 3, 4 To get 5, 6 Ways to get 7 And 2 Ways to get 11. So total of 15, therefore prob = 15/36.
Ravindra said:
1 decade ago
@Harshini.
Permutations are used for arrangement where as combinations are used for selection.
Ex: Arrange the name xyz then per is used.
Where as,
Select one among this xyz comb is used.
Permutations are used for arrangement where as combinations are used for selection.
Ex: Arrange the name xyz then per is used.
Where as,
Select one among this xyz comb is used.
Nilesh Patil said:
9 years ago
(1,1), (2,1), (2,3), (3,2), (4,1), (1,4), (4,3), (3,4), (5,2), (2,5), (6,1), (1,6), (6,3), (3,6), (6,5),(5,6)
If(1,1) is considered then n(E) becomes 16 then, what's wrong in above?
If(1,1) is considered then n(E) becomes 16 then, what's wrong in above?
Abs Rasel said:
7 years ago
Prime numbers
2={1,1}
3={1,2};{2,1}
5={1,4};{4,1};{2,3};{3,2}
7={1,6};{6,1};{2,5};{5,2};{3,4};{4,3}
11={5,6};{6,5}
Total 15 possible outcomes.
So, Probability is =15/36=5/12.
2={1,1}
3={1,2};{2,1}
5={1,4};{4,1};{2,3};{3,2}
7={1,6};{6,1};{2,5};{5,2};{3,4};{4,3}
11={5,6};{6,5}
Total 15 possible outcomes.
So, Probability is =15/36=5/12.
(3)
Harika said:
6 years ago
Hi when would be the sample space be 12 and when would it be 36? I mean if a dice is thrown twice or if two dice are thrown. What would be the difference in the sample space?
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