Question

If you draw a single card once from a deck of ordinary laying cards, what is the probability that it will be a 3 or a black card

Answer 1

The required probability = 0.5385

Explanation:

The no. of cards in a deck = 52

The event of having 3 in a draw of a single card = 4/52

The event of having a black card in a draw of a single card = 26/52

The event of having a black card and 3s = 2/52

Let T represent the event of having 3.

U to represent the event of having a black card; &

V to represent the event of having a black card that is 3s

Then the probability that it will be a 3 or a black card is;

P( T or U) = p(T) + p(U) - p(T and U)

P( T or U) = 4/52 + 26/52 - 2/52

P( T or U) = (4+26-2)/52

P( T or U) = 28/52

P( T or U)= 7/13

P( T or U) = 0.5385