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 and these are equally likely outcomes. What is the probability that it will point at:

(iv) a number less than 9

Answer 1

Sample space, S = {1, 2, 3, 4, 5, 6, 7, 8}
∴ n (S) = 8
Now,
Let D be the event where the arrow points at a number less than 9.
D = {1, 2, 3, 4, 5, 6, 7, 8}
$\therefore$ n (D) = 8
And,
P (D) = $\frac{n\left(D\right)}{n\left(S\right)}=\frac{8}{8}=1$
$\therefore$ Probability that the arrow will point at a number less than 9 = 1