Språkstatistik HT95:01

Class:   01
Date:    950905
Topic:   Introduction / Probability theory (1)

Homework exercise 1

1. We have two urns containing balls. Urn A contains three balls: one white ball and two black balls. Urn B contains five balls: two white balls and three black balls. We take a ball X from urn A and put it into urn B. Then we take a ball Y from urn B.
   • What is the probability that ball X is white?
   • What is the probability that ball X is black?
   • What is the probability that ball Y is white?
   • What is the probability that ball Y is black?
   • What is the probability that ball Y is white given that ball X is white?
   • What is the probability that ball Y is black given that ball X is black?