Question

There are $20$ girls and $15$ boys in a class. What is the ratio of the number of girls to the total number of students in the class?

Answer 1

Hint: First, we will divide the number of given girls in the class by the number of boys.
Then we will convert the obtained fraction in the simplest form that the fraction could be in to find the ratio of the number of the girls to the total number of students in the classroom.

Complete step-by-step solution:
Since from the given that we have the number of boys count is $15$ and then the number of girls count is $20$. Now we know the ratio is computed by dividing the number of girls by the number of boys.
Hence using the above students count values we get \[\dfrac{G}{B} = \dfrac{{20}}{{15}}\] where G is the girl's count and B is the number of boys count.
Since we know that the above form is not the simplest form because it can be even simplified with the multiply of $5$ in the numerator and the denominator.
Hence to get the simplest form, we have divided the common multiples and we get \[\dfrac{G}{B} = \dfrac{{\dfrac{{20}}{5}}}{{\dfrac{{15}}{5}}}\] and further solving we have \[\dfrac{G}{B} = \dfrac{{\dfrac{{20}}{5}}}{{\dfrac{{15}}{5}}} \Rightarrow \dfrac{4}{3}\]
Hence the total number of the students is $4 + 3 = 7$ (simplest form) where $4$ are the girls count and $3$ is the boys count.
Therefore, to find the ratio of the number of girls to the total number of students in the class is $4:7$ in simplest form.

Note: Since in the given question they asked to find the ratio of the number of girls to the total number of students in the class.
If suppose they asked the ratio of the number of girls to the number of boys then we have $4:3$ where $4$ are the girls count and $3$ is the boys count.
Also, if they asked to find the ratio of the number of boys to the total number of students in the class then we get $3:7$.
Hence the method is the same for all, and it will depend on the given question the answer may change according to that.