Aptitude - Probability - Discussion

N(E) = 1C1 + 1C1 = 1 + 1 = 2.

Ans. is : 1/13.

n(s) = 52C1 = 52; Because we need to find the probability of getting a queen of club OR-( / ) a king of spade.
n(E) = 4C1 = 4.
n(P) = 4/52 = 1/13.

What is mean a queen of club?

Most of the people said the answer is 1/26 but they don't understand or read the question carefully. In this question, the statement is clear that a one card is drawn from 52 cards, not 26, so why they, again and again, took sample space 26?

The correct answer is 2/13. Because the probability of getting queen is 4/52 i.e., 1/13 and same for the king of heart 1/13. this is because all the 4 types in the cards have 1 king, 1 Jack, 1 Queen and 1 Ace.

So the heart have its 1 king, 1 Jack, 1 Queen and 1 Ace, Diamond have its own and same for other.

@Kannan - Because we know that there is only 1 queen of club in 52 cards, here is no probability its definite so that's why we took 1+1.

You explained perfectly @Sonam.

For this question, I got the answer as 2/13. But how it is 1/26? I don't no please tell me.

Here you said, one queen or one king. So we have to consider either king or queen right? Then the anser will be 1/52. How it's 1/26?

Prob of 1 random selection n(S) = 52C1 = 52.

Queen of club = (13C1)/13 OR
King of heart = (13C1)/13.

So addition is n(E) = 2.

Finally,
p(E) = n(E)/n(S)

= 2/52 i.e 1/26.

WE HAVE ONLY 1 QUEEN IN A CLUB AND 1 KING IN HEART SO WE HAVE TWO

EVENTS ONLY

So,

P(E) = 1/52 + 1/52

= 2/52

= 1/26.