Number Systems CLASS 9

Which of the following expressions represents a positive number? 

• -4.5 - (-5)
• -1/8 + (-5/8)
• 6.1 + (-6.2)
• -3/4 - (-2/3)

Classify the number: 0

• natural, whole, integer, rational, real

• integer, irrational, real

• irrational, real

• whole, integer, rational, real

A non-repeating or non-terminating decimal is classified as ________________.

• rational, real

• irrational, real

• integer, rational, real

• whole, integer, irrational, real

Classify the number:

• integer, rational, real

• rational, real

• irrational, real

• whole, integer, rational, real

Which of the following is irrational?

• 
  

  $\sqrt{\frac{4}{9}}$
  

• $\sqrt{\frac{12}{3}}$

• $\sqrt{7}$

• $\sqrt{81}$

 $2\sqrt{3}+\sqrt{3}$  is equal to

•  $2\sqrt{6}$  

• 6

•  $3\sqrt{3}$  

•  $4\sqrt{6}$  

The number obtained on rationalising the denominator of  $\frac{1}{\sqrt{7}-2}$  is

•  $\frac{\sqrt{7}+2}{3}$  

•  $\frac{\sqrt{7}-2}{3}$  

•  $\frac{\sqrt{7}+2}{5}$  

•  $\frac{\sqrt{7}+2}{45}$  

After rationalising the denominator of 

 $\frac{7}{3\sqrt{3}-2\sqrt{2}}$  , we get the denominator as

• 13

• 19 

• 5

• 35

The square root of which number is rational

• 7

• 11

• 0.04

• 13

the number is (  $3-\sqrt{3}$ )(3 $-\sqrt{3}$ )

• an irrational number

• a rational number

• not a natural number

• none of these