Godfrey plays a game in which he throws two fair six sided dice. If he rolls two sizes, he wins 20p, if he rolls one six, he wins 10p, otherwise he wins nothing. He pays 5p to enter.

Write out the probability distribution of X, the amount Godfrey gains in one turn.

(3 marks)

The Probabilty distribution for the amount Godfrey gains in one turn is then given as

X ||| P(X)

15p | 0.0278

5p | 0.278

-5p | 0.6942

Step-by-step explanation:

If random variable X represents the amount Godfrey gains in one turn.

There are 3 different possible outcomes for X.

- Godfrey pays 5p to enter the game and gets two sixes and wins 20p.

Net gain = 15p

Probability of getting two sixes from two fair dice

= (number of outcomes with two sixes) ÷ (total number of outcomes)

number of outcomes with two sixes = 1

total number of possible outcomes = 36

Probability of getting two sides from two fair dice = (1/36) = 0.0278

- Godfrey pays 5p to enter the game and gets only one six and wins 10p.

Net gain = 5p

Probability of getting one six from either of two fair dice

= (number of outcomes with one six) ÷ (total number of outcomes)

number of outcomes with one six = 2 × n[(6,1), (6,2), (6,3), (6,4), (6,5)] = 2 × 5 = 10

total number of possible outcomes = 36

Probability of getting two sides from two fair dice = (10/36) = 0.278

- Godfrey pays 5p to enter the game and doesn't win anything

Net gain = -5p

Probability of not getting two sixes or one six.

= 1 - [(Probability of getting two sixes) + (Probability of getting one six on.wither dice)]

= 1 - 0.0278 - 0.278 = 0.6942

Probability of getting not getting two sixes or one six = 0.6942

The Probabilty distribution for the amount Godfrey gains in one turn is then given as

X ||| P(X)

15p | 0.0278

5p | 0.278

-5p | 0.6942

Hope this Helps!!!