math
posted by omar .
50 red cars and 30 white and 20 blue what is the probability of 2 cars from the same colors ?

The probability would be red because it has the most cars

10

Your question is incomplete.
Are you choosing 2 cars ? It doesn't say.
Assume we are choosing 2 cars and you want the prob that they are both of the same colour.
The could be RR or WW or BB
prob(RR) = C(50,2)/C(100,2) = 1225/4950 = 49/198
prob(WW) = C(30,2)/C(100,2) = 435/4950 = 29/330
prob(BB) = C(20,2)/C(100,2) = 190/4950 = 19/495
sum of those = 37/99
prob of same colour = 37/99