Probability of selecting all democrates for a three person commitee means you will select
a democrat as your first choice and a democrat as your second choice and a democrat as your third choice.
Total of candidate in the house of representative is number of republican and democrates = 234 + 201
= 435
P (democrat at first choice) = number of democrat / total
= 201/435
P (democrat at second choice) = number of democrat / total
= 200/434
number of democrat become 200 because one has been at the first choice an not being replaced
total has become 434 because one has been selected and not being replaced
P (democrat at third choice) = 199 / 433
number of democrat become 199 because one has been at the first choice an not being replaced
total has become 432 because one has been selected and not being replaced
P (democrat at first choice) * P (democrat at second choice) * P (democrat at third choice) =
201/435 * 200/434 * 199/433 =
0.098
