STATISTICS PROBABILITY QUESTION! Please help! 10 points!?

Question

The probability of a property being sold by a sole agent in the first week of listing is 20%. In a random sample of eight properties listed by a single real estate agent.

a) What is the probability that none sell in the first week?

b) What is the probability that at least one sells in the first week?

c) What is the probability that all sell in the first week?

Thanks in advance.

Answer 1

Here's what I get:

a) P(none sell)=(1-.2)^8=(.8)^8= about .1678 or 16.78%

b) P(at least one sells) = 1 - P(none sell) = 1- .1678 = about .83 or 83%

c) P(all sell) = (.2)^8 = 0.00000256 or about 0.000256%