## Tuesday, 29 November 2011

### Guess whats in the bag!

Probability in year 7 - So we put 15 different coloured sweets in a bag and then pulled 1 out at random and noted the colour and then put it back. We repeated this exercise a number of times and got the tally chart above. Each student was allowed 2 guesses at the contents of the bag with the first successful guess winning the sweets! The challenge was 'what' to guess and 'when' to guess! Guess early and you get the first chance at winning the sweets, but you have less information to help you. Wait too long and somebody might get there first. Some tricky decisions! The whole point is of course that the more times you repeat the experiment, the more likely the tally chart is to show the right proportions. What colour do you think the sweets were? Could there be a purple one in there somewhere? Are there definitely more greens? We had a lot of fun. These and similar games for playing with this idea are published here - Guess my colour, Roll'em and In a spin.

#### 1 comment:

1. Seems fun, have you heard of the Monty hall problem it is another good probability problem