A standard deck of cards has 52 cards, and 13 of these are hearts, as there are 4 suits, and 52/4=13. This means the probability of choosing a heart card from a deck of cards is 1/4, or 25%. Now to find the probability of doing this from 3 decks in a row, we simply cube 1/4 to get 1/64, and in percentage this is ~1.56%.
To get this, you divide the smaller number by the larger one and get 0.5882... 500 is about 59% of 850, so to find the percent lost, you subtract that from 100 to get 41% decrease
