Suppose that a person selects a card at random from a deck of 52 cards and tells us that the selected card is red.Find the probability that the card is the kind of hearts given that it is red?

1 Answer
Feb 19, 2018

#1/2#

Explanation:

#P["suit is hearts"] = 1/4#
#P["card is red"] = 1/2#
#P["suit is hearts | card is red"] = (P["suit is hearts AND card is red"])/(P["card is red"])#
#=(P["card is red | suit is hearts"]* P["suit is hearts"])/(P["card is red"])#
#= (1*P["suit is hearts"])/(P["card is red"])#
#= (1/4)/(1/2)#
#=2/4#
#=1/2#