Answer:
a) the probability that no sales are made in 10 calls is 0.1969
b) the probability more than 1 sales are made in 20calls is 0.8244
Step-by-step explanation:
Given that;
p = 0.15
q = 1 - p = 1 - 0.15 = 0.85
a) probability that no sales are made in 10 calls will be;
n = 10
p(x=0) = ¹⁰C₀(0.15)⁰ (0.85)¹⁰ = 0.1969
Therefore the probability that no sales are made in 10 calls is 0.1969
b) probability more than 1 sales are made in 20calls
n = 20
let y be number of sales in 20 calls
y∪Bin(n=20, p=0.15)
p(y > 1) = 1 - [p(y=0) + p(y=1)
= 1 - [²⁰C₀(0.15)⁰ (0.85)²⁰ + ²⁰C₁(0.15) (0.85)¹⁹] = 0.8244
Therefore the probability more than 1 sales are made in 20calls is 0.8244
