Theory:

1. Conversion of per cent into fraction
To convert a per cent into a fraction, divide it by \(100\) and remove the "\(\%\)" sign.
Let, \(a\)\(\%\) \(=\) a100 [Per cent \(=\) Fraction]
Example:
(i) 37% \(=\) 37100
 
(ii) 22% \(=\) 22100
Note: Per cent is a fraction with a denominator of \(100\), and the numerator of this fraction is called Rate per cent.
  
  
2. Conversion of fraction into per cent
To convert any fraction to per cent, multiply it by \(100\) and put the per cent sign(\(\%\)).
Let, ab=[ab×100]%
     (fraction)  (per cent)
Example:
210=[210 ·100]% \(=\) 20\(\%\)
  
3. Conversion of percentage into fraction
To convert the per cent into a ratio, change it to a fraction by dividing it by \(100\) and removing the per cent (\(\%\)) sign. Finally, reduce the obtained fraction to the simplest form.
Example:
(i) \(25\)\(\%\)
 
\(= 25/100\)
 
\(= 1/4\) or \(1:4\).
 
(ii) \(0.4\)\(\%\)
 
\(= 0.4/100\)
 
\(= 4/1000\)
 
\(= 1/250\) or \(1:250\).