Question

In a class, there are $ 20 $ boys and $ 40 $ girls. What is the ratio of the number of boys to the number of girls?

Answer 1

Hint: To solve this problem to need to know the ratio and proportion concept. Here, first of all, read the question twice and then frame the mathematical expression by the ratio of the number of boys to the number of girls. On framing the given data mathematically half of the solution can be done.

Complete step-by-step solution:
Given data: There are $ 20 $ boys and $ 40 $ girls
The ratio of boys to girls is the fraction where the numerator is the total number of boys and the denominator is the total number of girls.
Ratio $ = \dfrac{{20}}{{30}} $
Find the factors for the above expression –
Ratio $ = \dfrac{{2 \times 10}}{{3 \times 10}} $
Common factors from the numerator and the denominator cancel each other and therefore remove from the numerator and the denominator.
Ratio $ = \dfrac{2}{3} $

So, the ratio of the number of boys to the number of girls is $ 2:3 $

Note: Read the question twice and then frame the equation accordingly. The ratio of the number of girls is to boys and boys is to girls is two different ratios and frame it wisely. The ratio is defined as the comparison between two numbers without any units. Whereas, when two ratios are set equal to each other are known as the proportion. Four numbers a, b, c, and d are called to be in the proportion. If $ a:b = c:d $ whereas, four numbers are said to be in constant proportion if the terms \[\] $ a:b = b:c = c:d $