What is Ratio

The ratio of two quantities a and b in the same units, is the fraction \begin{aligned} \frac{a}{b} \end{aligned} and we write it as a : b.

In the ratio a : b, we call a as the first term which is also know as antecedent and b, the second term which is also called consequent.

For example:
\begin{aligned}
4:5 = \frac{4}{5}
\end{aligned}
Here 4 is antecedent and 5 is consequent

Important Rule :
The multiplication or division of each term of a ratio by the same non-zero number does not affect the ratio.

For example: 2:3 = 4:6 = 6:9