A person selects 3 cards from an ordinary deck and replaces each card after it is drawn. Find out the probability that the person will get at least one heart
We could either:
a) calculate the probabilitys that we can get exactly one heart, then the probability that we can get exactly two hearts, and then the probability that we can get exactly three hearts and add those answers together
b) calculate the probability that we can get three non-hearts and subtract that value from 100%, which is 1.000.
The second choice is easier:
-- the probability that we get three non-hearts (with replacement) is: 39/52 x 39/52 x 39/52 = 27/64
-- subtracting this from 1.000 leaves us with: 37/64.