statistics binomial probability

Question

If a seed is planted, it has a 60% chance of growing into a healthy plant.

If 7 seeds are planted, what is the probability that exactly 2 don't grow?

Answer 1

P(X=2)

= C(7,2)•(0.60)⁵(0.40)²

= 7!/[2!(7-2)!] • 0.0124416

= (7*6)/(2*1) • 0.0124416

= 24*0.0124416

= 0.2985984 <-- no indication of rounding

Therefore, there's about a 30% chance that exactly 2 of the 7 seeds don't grow.

Hope this helped!