Statistics

[Guest]

A sales man knows that, on each visit to a customer, the probability of a sale is one fifth. Each day he makes three independent visits to customers.

Calculate the probability that, on a randomly selected day:
(a) all three visits result in sales.
(b) exactly two visits results in sales.
(c) less than two visits results in sales

[shyamjayakannan]

a) [tex]\frac{1}{5}\times\frac{1}{5}\times\frac{1}{5}=\frac{1}{125}=\boxed{0.008}[/tex]

b) [tex]^3C_2\times\frac{1}{5}\times\frac{1}{5}\times\frac{4}{5}=\frac{12}{125}=\boxed{0.096}[/tex]

c) [tex]1-(a)+(b)=\boxed{0.896}[/tex]