Question

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

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

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]

i) Total number of users of Dell or Microsoft mouse = 26 + 23 = 49.
Probability that a person uses a computer mouse of Dell or Microsoft
= $\frac{49}{100}=\mathrm{0.49.}$

ii) Number of people who do not use Logitech, Dell or Microsoft mouse (others) = 19.
Probability that a person does not use Logitech, Dell or Microsoft mouse = $\frac{19}{100}=\mathrm{0.19.}$