Binomial Distribution

A family has planted 15 oak tree saplings in their backyard. Their garden centre has informed them that that the probability that any given sapling will thrive is 0.8. Let x be the number of saplings that thrive.

a) What is the probability that exactly 8 saplings will thrive?

b) What is the probability that less than 12 saplings will thrive?

c) What is the probability that 10 or more saplings will thrive?

d) What is the mean for this probability distribution? What is the probability that exactly this number of saplings will thrive?