Question

You spin a spinner that has 8 equal-sized sections numbered 1 to 8. Find the theoretical probability of landing on the given section(s) of the spinner.
(i) section 1 (ii) odd numbered section (iii) a section whose number is a power of 2. [4 MARKS]

Answer 1

Concept : 1 Mark
Sub-parts : 1 Mark each

Since the sections have equal size, each section is equally probable.
The probability of falling on each section is therefore $\frac{1}{8}$.

(i) Hence, probability of falling on section 1 is $\frac{1}{8}$.

(ii) There are four odd numbered sections. Hence, probability is $\frac{4}{8}$ = $\frac{1}{2}$.

(iii) There are 3 numbers here which are powers of two, namely 2, 4 and 8. Hence, the required probability is $\frac{3}{8}$.