I am not too sure did i do these questions correctly.

A salesperson contacts eight potential customers per day. From past experience, we know that the probability of a potentail customer making a purchase is 0.10.

a) What is the probability the salesperson will make at least two sales in a day?

-Do you use binomial formula for this question, which is 1 - 0.4305 + 0.3826 = 0.1869 ?

b) What percentage of days will the salesperson not make a sale?

Would that be caculating P(0). Use the binomial formula again and get 43.05%?

c) What is the expected number of sales per day?

8* 0.1 = 0.8?

would anybody please check my answers thanks.