Ffion goes to a fair. There she finds a game that involves rolling 2 balls down an inclined plane so that each ball finally settles in one of five slots and scores the number of points allocated to that slot.
The slots are allocated the following values: 2, 4, 7, 4, 2.
It is possible for both balls to settle in the same slot.
It may be assumed that each slot is equally likely to accept either ball.
The player's score is the sum of the points scored by each ball.
If it costs 10p for each game and Ffion receives back a number of pence equal to her score, how much would Ffion expect to lose or gain in 50 games?
| Total Score | Probability |
|---|---|
| 4 | 4/25 |
| 6 | 8/25 |
| 8 | 4/25 |
| 9 | 4/25 |
| 11 | 4/25 |
| 14 | 1/25 |
Mean score = ((4 x 4) + (6 x 8) + (8 x 4) + (9 x 4) + (11 x 4) + (14 x 1)) ÷ 25 = 7.6
50 games at 10p each = £5.00
The below image shows a fish made from matchsticks
The challenge is to make the fish swim in the opposite direction by moving 3 of the matches
