Question

Classify each number as rational or irrational.

0.167

2/9

​​π​

225√

Answer 1

A number is rational if we can write that number as a fraction.

A number is irrational if we can not write as a fraction. This means if a number has non repeating and non terminating decimal values then it is an irrational number.

Now let us look at our given numbers one by one.

`0.167`

We can write
`0.167` as
`(167)/(100)` . Hence it is a rational number.

`(2)/(9)` This number is already written as fraction. It is a rational number.

`\pi` We can not write
`\pi` as a fraction because the equivalent decimal values of
`\pi` are non repeating and non terminating. Therefore
`\pi` is an irrational number. Remember that
`(22)/(7)` is just an approximation for
`\pi`. It isn't the actual value of
`\pi`.

`\sqrt225` is equivalent to 15. We can write 15 as a fraction like
`(15)/(1)`. Therefore
`\sqrt225` is a rational number.

Answer 2

`0.167\ -\ rational\\\\(2)/(9)\ -\ rational\\\\\pi\ -\ irrational\\\\√(225)=15\ -\ rational`