Question

A survey was conducted to find out which brands of computer mouse different people used. The data collected from a 100 people is as follows:

$$\begin{array}{cc}Brand& Frequency\\ Logitech& 32\\ Microsoft& 26\\ Dell& 23\\ Others& 19\end{array}$$

Find the probability that a person
(i) uses Dell or Microsoft
(ii) does not use either Logitech, Dell or Microsoft. [3 MARKS]

Answer 1

Solution: 1.5 Marks each
Total number of users of Dell or Microsoft mice = 26 + 23 = 49.
Probability that a person uses Dell or Microsoft = $\frac{49}{100}$ = 0.49.
Number of people who do not use Logitech, Dell or Microsoft = 19.
Probability that a person does not use Logitech, Dell or Microsoft = $\frac{19}{100}$ = 0.19.