Question

how do you find the theoretical probability of two events

Answer 1

can you be a bit more specific?
the union of two events? the intersection of two events?

Answer 2

im trying to find the probability of choosing a $1 and a $5 if there are four $1 three $5 and two $10s

Answer 3

9 bills in total right?

Answer 4

correct

Answer 5

man i had all those numbers wrong, sorry

Answer 6

first $1, then $5
probability is
\[\frac{4}{9}\times \frac{3}{8}\] probability first $5 then $1 is the same
\[\frac{3}{9}\times \frac{4}{8}\]
answer is therefore
\[2\times \frac{4}{9}\times \frac{3}{8}\]

Answer 7

other method is
\[\frac{\binom{4}{1}\times \binom{3}{1}}{\binom{9}{2}}\]
\[=\frac{4\times 3}{36}\]

Answer 8

thanks.