Aptitude - Probability - Discussion
Discussion Forum : Probability - General Questions (Q.No. 13)
13.
Two cards are drawn together from a pack of 52 cards. The probability that one is a spade and one is a heart, is:
Answer: Option
Explanation:
Let S be the sample space.
| Then, n(S) = 52C2 = | (52 x 51) | = 1326. |
| (2 x 1) |
Let E = event of getting 1 spade and 1 heart.
 n(E) |
= number of ways of choosing 1 spade out of 13 and 1 heart out of 13 |
| = (13C1 x 13C1) | |
| = (13 x 13) | |
| = 169. |
| P(E) = |
n(E) | = | 169 | = | 13 | . |
| n(S) | 1326 | 102 |
Discussion:
42 comments Page 5 of 5.
Deepika said:
2 years ago
We have only 4 hearts in total in a deck of 52 cards. So, shouldn't it be 4C1? Why are we using 13C1 for hearts?
Someone, please explain.
Someone, please explain.
(2)
Arshath Ahamed A said:
1 year ago
The answer is Simple,
We need to choose 2 cards one is from spade and another is from heart.
The total cards are 52.
So In the first pick, we will take either spade or heart so the probability is (13 + 13) = 26.
In the second pick, we need to take the rest type (heart or spade) so it is 13 and the total no of cards decreased by 1 due to the first pick.
So the answer is,
P (T) = 26/52 * 13/51,
=> 1/2 * 13/51,
=> 13/102.
We need to choose 2 cards one is from spade and another is from heart.
The total cards are 52.
So In the first pick, we will take either spade or heart so the probability is (13 + 13) = 26.
In the second pick, we need to take the rest type (heart or spade) so it is 13 and the total no of cards decreased by 1 due to the first pick.
So the answer is,
P (T) = 26/52 * 13/51,
=> 1/2 * 13/51,
=> 13/102.
(3)
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