A hint to get started
Game winnings, a mode and a tournament cutoff
A bag contains 4 red, 5 blue and 6 green balls. The balls are indistinguishable except for their colour. A trial consists of drawing a ball at random from the bag, noting its colour and replacing it in the bag. A game is played by performing 10 trials in all.
The player receives $0.50 for every blue ball drawn in a game. He receives nothing if balls of other colours are drawn.
(a) Find the probability that, in a game, he receives
(i) exactly $3,
(ii) more than $2.50,
(b) Find also the amount a player is most likely to receive.
(c) At the start of a tournament, each player plays the above game once. Players who earned more than $ proceed to the next round. Find the least value of such that, in a random sample of 10 players, the probability that all the 10 players proceed to the next round is less than 0.1.
CJC · Discussion · Question 8
Model the number of blue balls first; each blue is worth half a dollar.