Question

game stores made claims that the probability that a custom prefer the deluxe model to the standard model of a product is 30%. what is probability that at most two out of 10 customers will prefer the deluxe model.

Answer 1

"at most two out of 10 customers will prefer the deluxe model "
means:
none prefer + 1 prefers + 2 prefer
= C(10,0) .3^0 .7^10 + C(10,1) .3^1 .7^9 + C(10,2) .3^2 .7^8
= ....