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 6 of 7.
Ganesh Sang said:
1 decade ago
Please in every example we need to find samples or experiment samples or there is any shortcut for easily getting number of prime number or sum of two numbers as a prime ?
Siva said:
1 decade ago
Prime number means the we gets only one time. i.e., 1*2=2 only once we get 2. But for 4 1*4=4, 2*2=4 now we get 4 for 2 times in-terms of multiplication.
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.
Ramya said:
1 decade ago
They have left out 6, 3 and 3, 6 then 5, 6 and 6, 5. These also should be included then the total probability becomes 1/2.
Rakesh said:
1 decade ago
Why we not chosen (2, 2) because it also prime number and it divisible by only 2?
Olamikan adesanmi said:
1 decade ago
No wot they mean is that the sum (total) is a prime number. So as for (1, 4) , (1, 6) , the sum are 5 and 7 which are prime numbers.
Anil singh said:
1 decade ago
Prime number divisible by 1 and that nimber only but in the case (1,4), (1,6) etc divided by other number like 1,2,3
Please explain.
Please explain.
Prasad said:
1 decade ago
Hey why we cant take (1,3),(2,2,),(3,1)etc we can take others also na?
So please solve this in easy way.
So please solve this in easy way.
Harshini said:
1 decade ago
Please tel me where to use permutation and where to use combinations. ?
Sujatha said:
1 decade ago
Could you please tel me any short methods for Probability?
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