### 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, $$a$$$$\%$$ $$=$$ $\frac{a}{100}$ [Per cent $$=$$ Fraction]
Example:
(i) $37%$ $$=$$ $\frac{37}{100}$

(ii) $22%$ $$=$$ $\frac{22}{100}$
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, $\frac{a}{b}=\left[\frac{a}{b}×100\right]%$
(fraction)  (per cent)
Example:
$\frac{2}{10}=\left[\frac{2}{10}·100\right]%$ $$=$$ 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 $$1:250$$.