A store has eight toasters left for sale. Five of the toasters work perfectly and three of the toasters are defective. A salesperson sells two of the eight toasters. Let T denote the number of defective toasters that were sold. Find P(T>µ)

Question

A store has eight toasters left for sale. Five of the toasters work perfectly and three of the toasters are defective. A salesperson sells two of the eight toasters. Let T denote the number of defective toasters that were sold. Find P(T>µ)

I calculated µ to be 3/4.

Answer 1

Prob(defect) = 3/8

prob(good) = 5/8

Prob(2 of the 8 are defective) = C(8,2) (3/8)^2 (5/8)^6
= appr .235
Prob(1 of the 8 is defective) = C(8,1) (3/8) (5/8)^7
prob(both are good) = (5/8)^8

See what you can do with that