Question

[1] Which of the following is a rational number ?

Answer 1

To find :

the Rational number among :

$\bold{a. \: \sqrt{2} } \\ \bold{b. \: 0.3} \\ \bold{ c. \: \: \pi} \\ \bold{d. \: \sqrt{7} }$

What is a Rational number:

all the real numbers which can be denoted in the form of p/q , where q ≠ 0 , is called a Rational number.

eg. 0.2 = 2/10 hence, this a Rational number.

$\bold{ eg. \: \sqrt{4} = 2 \: = \frac{2}{1} \: hence \: this \: is \: a \: rational \: number}$

Solution :

$\bold{a. \: \sqrt{2} = 1.41421356...} \:$

it can't be converted in p/q form

hence, this an irrational number .

$\bold{b. \: 0.3 = \frac{3}{10} }$

hence, this is a Rational number

$\bold{ c. \: \pi = 3.1415926}$

hence, this is an irrational number

$\bold{ d. \: \sqrt{7} = 2.64575131...}$

hence, this is an irrational number

hence, only b) 0.3 is a Rational number.