Question

A spinner is divided into 8 section of equal size. The sections are numbered 1 through 8. Use this information to determine the probability of the needle landing on

Answer 1

1) 1/8

2) 1/2

Step-by-step explanation:

1)

First of all, we notice that the spinner is divided into 8 sections of equal size.

So the number of sections is

n = 8

Secondly, we note that each section has the same size: this means that the probability of the spinner landing on each section is the same.

The probabilty of a certain event A to occur is given by

$p(A)=\frac{a}{n}$

where

a is the number of successfull outcomes (in which A occurs)

n is the total number of possible outcomes

Here we want to find

$p(7)$ = probability that the spinner lands on section 7

Here we have:

$a=1$ (only 1 outcome is successfull: the one in which the spinner lands on section 7)

$n=8$

Therefore, the probability is

$p(7)=\frac{1}{8}$

2)

Here we want to find the probability that the spinner lands on an even numbered section.

As before, the total number of possible outcomes his:

$n=8$

which corresponds to: 1, 2, 3, 4, 5, 6, 7, 8

The even-numbered sections are:

2, 4, 6, 8

So, the number of successfull outcomes is

$a=4$

Because there are only 4 even-numbered sections.

Therefore, the probability that the spinner lands on an even numbered section is:

$p(e)=\frac{a}{n}=\frac{4}{8}=\frac{1}{2}$