Question 1
Two dice are thrown. One
is biased so that the probabilities of throwing the six numbers are
all different. The other die is unbiased. Calculate the
probability that the numbers shown on the two dice are the same.
Question 2
A bag contains 8 black balls and 1 white ball. A second contains
7 black balls. Four balls are taken at random from the first bag
and palced in the second bag. Find the probability that the white
ball is now
(a)
first, dice or die?
a) total probability = both dice 1 + both dice 2 + both dice
3...
=a x 1/6 + b
x 1/6 +.....
= a/6 + b/6 + c/6
....
=
(a+b+c+...)/6
= 1/6
where a, b, c is the probability for each die.