Ratio Formula
We use the ratio formula while comparing the relationship between two numbers or quantities. The ratio is defined as the relation between the quantities of two or more objects and it indicates the amount of one object contained in the other. The general form of representing a ratio of two quantities say a and b is
a : b
where,
 a = Antecedent
 b = Consequent
Let us understand the ratio formula in detail in the following sections.
What is the Ratio Formula?
Ratio is relation between the quantities of two or more objects, indicating the amount of one object contained in the other. A ratio can be represented in the form of a fraction using the ratio formula. The ratio formula for any two quantities say a and b is given as,
a:b = a/b
Since a and b are individual amounts for two quantities, the total quantity combined is given as (a + b). Let us understand the ratio formula better using a few solved examples.

Example 1: In a class of 70 students, 43 are girls and the remaining are boys. Using the ratio formula, find the ratio of the total number of boys to the number of girls.
Solution:
To find: Ratio of the number of boys to the number of girls
Given:
Total number of students = 70
Number of girls = 43
Number of boys = Total number of students  Number of girls
= 27
Using ratio formula,
The ratio of number of boys to the number of girls = Number of boys: Number of girls = 27:43
Answer: Ratio of the number of boys to the number of girls = 27:43

Example 2: The ratio of x and y is 6:5. If x = 78, what is the value of y?
Solution:
To find: Value of x
Given:
Ratio of x to y = 6:5
Using ratio formula,
x:y = 6:5
x/y = 6/5
78/y = 6/5
y = (5/6) × 78
y = 65
Answer: Value of y = 65