Question

It is equally probable that the pointer on the spinner shown will land on any one of the eight regions, numbered 1 through 8. If the pointer lands on a borderline, spin again. Find the probability that the pointer will stop on an odd number or a number less than 4.This is contemporary mathmatics class in college, by the way...

Answer 1

Sample space = {1, 2, 3, 4, 5, 6, 7, 8}

A = odd number = {1, 3, 5, 7}

count = 4

B = number less than 4 = {1, 2, 3}

count = 3

`\begin{gathered} A\cap B=\lbrace1,3\rbrace \\ \\ P(A\cup B)=P(A)+P(B)-P(A\cap B) \\ \\ \Rightarrow P(A\cup B)=(4)/(8)+(3)/(8)-(2)/(8)=(5)/(8) \end{gathered}`

The probability is 5/8