Question

200 people were surveyed to see which of the four mentioned snacks below that people prefer. The data is as shown in the table.

$\begin{array}{cc}\text{Snack}& \text{Number of people}\\ \text{Pizza}& 42\\ \text{Sandwich}& 50\\ \text{Burger}& 74\\ \text{Ice cream}& 34\end{array}$

What is the probability that a person

(i) prefers ice cream
(ii) does not prefer ice cream.
(iii) are (i) and (ii) complementary? [ 1 MARK]

Answer 1

Concept: 0.5 Mark
Solution: 0.5 Mark

Probability that a person prefers ice cream
$=\frac{34}{200}=\mathrm{0.17.}$

Probability that a person does not prefer ice cream = 1 – 0.17 = 0.83.

The two events are complementary because every outcome is a part of exactly one of these two events.