Question

A game of chance consists of spinning an arrow which comes to rest pointing at one of the numbers $1,2,3,4,5,6,7,8$ (see Fig. $15.5$), and these are equally likely outcomes. What is the probability that it will point at
(i) $8$?
(ii) an odd number?
(iii) a number greater than $2$?
(iv) a number less than $9$?

Answer 1

i) $P\left(8\right)=\frac{1}{8}$

ii)

$P($Odd number$)=\frac{\text{Number of odd numbers}}{\text{Total number of numbers in the chart}}$

$P($Odd number$)=\frac{4}{8}=\frac{1}{2}$

iii)

$P($Number $>2)=\frac{\text{Number of numbers}>2}{\text{Total number of numbers in the chart}}$

$P($Number $>2)=\frac{6}{8}=\frac{3}{4}$

iv)

$P($Number $<9)=\frac{\text{Number of numbers}<9}{\text{Total number of numbers in the chart}}$

$P($Number $<9)=\frac{8}{8}=1$