Five cards are drawn from a well-shuffled pack of 52 cards. Find the probability that all the five cards are hearts.
given: pack of 52 playing cards
formula: 
five cards are drawn from the given deck
we have to find the probability that all of them are hearts
total possible outcomes of one card from the pack is 52C1
therefore n(S)= 52C5=2598960
let E be the event that all cards belong to hearts
n(E)=13C5=1287
probability of occurrence of the event is
40