Question

A standard 52 deck of cards are placed in a container. What is the probability that a card randomly selected from the container is a black card or 4?

Answer 1

`(7)/(13)`

Explanation:

Total Number of cards in a standard deck, n(S)=52

In a standard deck, there are 4 suits, 2 suits are black and 2 suits are red.

Number of Black Cards n(B)=26

Number of 4 cards, n(F)= 4

Number of Black cards with 4 on it,
`n(B\cap F)=2`

`P(B\cup F)=P(B)+P(F)-P(B\cap F)\\=(26)/(52) +(4)/(52) -(2)/(52) \\=(28)/(52) \\\\P(B\cup F)=(7)/(13)`

Therefore, the probability that a card randomly selected from the container is a black card or 4 is 7/13.