What is the probability of picking a 4 a 5 or a 7 from a standard deck of cards?
There are 52 cards in a standard deck.
There are 4 ways to pick a 4 (one each of hearts, diamonds, clubs, and spades), 4 ways to pick a 5, and 4 ways to pick a 7.
Therefore, the total number of ways to pick a 4, 5, or 7 is 4 + 4 + 4 = 12.
The probability of picking a 4, 5, or 7 from a standard deck of cards is 12/52 = 3/13 or approximately 0.231 or 23.1%.