how many bit string of length 12 contain at least three 1s? 2)
A coin is flipped 10 times where each flip comes up either heads or tails. how many possible outcomes contain at most three tails? 3)
thirteen people on a softball team show up for a game. How many ways are there to choose 10 players to take the field? 4)
a club has 25 members. How many ways are there to choose four members of the club to serve on an executive committee? 5)
how many ways are there for a horse race with four horses to finish if ties are possible? (any number of the four horses may tie).