prob(success) = 3/4
prob(fail) = 1/4
prob(2 of 11 to fail)
= C(11,2)(1/4)^2 (3/4)^9
= .258
check my arithmetic
If a seed is planted, it has a 75% chance of growing into a healthy plant.
If 11 seeds are planted, what is the probability that exactly 2 don't grow?
1 answer