Question

The probability that a salesman makes a sale on a visit to a prospective client is 0.2. What is
the probability that, in 2 visits, of:
i) making no sales
ii)making more than one sale

Answer 1

solution

Probability of success $p=0.2$

Let $X$ be the number of sales made out of the 2 attempts.

$$P(X=x) =\ _nC_x * p^x *(1-p)^{n-x}$$

Part i) making no sales

$P(X=0)$

$$=\ _2C_0 * 0.2^0 *(0.8)^{2}= 0.64$$

answer: 0.64

Part ii) making more than 1 sale

$P(X>1) = P(X=2)$

$=\ _2C_2 * 0.2^2 *(0.8)^{0}= 0.04$

answer: 0.04