Stage: 2 Challenge Level: 
Bipin is playing in a game show. The host tells Bipin that there are 10 balls hidden in a box - 5 are Red, 3 are Yellow and 2 are Blue. Bipin pulls out his first ball. It's Red and he wins a large sum of money. Now his choices are:
- He can stop playing and take his prize.
- He can pull out another ball - if it's Red he doubles his money, if it's Yellow he leaves with nothing, if it's Blue he can pick one last ball.
What should Bipin do? Why?
Working systematically. Probability. Equally likely outcomes. Conditional probability. Combining probabilities. Experimental probability. Interactivities. Dice. Tree diagrams. Theoretical probability.
Published February 2000.
Copyright © 2007. University of Cambridge. All rights reserved.
NRICH is part of the family of activities in the Millennium Mathematics Project, which also includes the Plus and Motivate sites.
email: nrich@damtp.cam.ac.uk