STATISTICS
posted by BETH .
The seeds of the garden pea are either yellow or green. A certain cross between pea plants produces progeny in the ratio 3 yellow:1 green. If four randomly chosen progeny of such a cross are examined, what is the probability that:
a)3 are yellow and 1 is green
b)all 4 are yellow
c)all 4 are the same color

p yellow = 3/4
p not yellow = 1/4
n = number of trials = 4
from pascal's triangle or binomial distribution table or calculation for n = 4
P(0y) = 1 (3/4)^0 (1/4)^4
P(1y) = 4 (3/4)^1 (1/4)^3
P(2y) = 6 (3/4)^2 (1/4)^2
P(3y) = 4 (3/4)^3 (1/4)^1
P(4y) = 1 (3/4)^4 (1/4)^0
I think you can get it from there