let A denote the event that the card drawn is king and B denote the event that card drawn is queen.
In a pack of 52 cards, there are 4 king cards and 4 queen cards
Given : P(A) = \(\frac{4}{52}\), P(B) = \(\frac{4}{52}\)
To find : Probability that card drawn is king or queen = P(A or B)
The formula used : Probability =
\(\frac{favourable\,number\,of\,outcomes}{total\,number\,of\,outcomes}\)
P(A or B) = P(A) + P(B) - P(A and B)
P(A) = \(\frac{4}{52}\) (as favourable number of outcomes = 4 and total number of outcomes = 52)
P(B) = \(\frac{4}{52}\) (as favourable number of outcomes = 4 and total number of outcomes = 52)
Probability that card drawn is king or queen = P(A and B)= 0
(as a card cannot be both king and queen in the same time)
P(A or B) = \(\frac{4}{52}+\frac{4}{52}\) – 0
P(A or B) = \(\frac{4+4}{52}\) = \(\frac{8}{52}\) = \(\frac{2}{13}\)
P(A or B) = \(\frac{2}{13}\)
Probability of a card drawn is king or queen = P(A or B) = \(\frac{2}{13}\)