Question

85% of the total of 500 students in the school are the boys. What will be the number of girls?

Answer 1

Hint: First of all, find the number of boys out of 500 students by using
\[\text{Number of boys}=\dfrac{\text{Percentage of boys }\times \text{ Total number of students}}{100}\]
Subtract the number of boys from total students to get the number of girls.

Complete step-by-step solution -
We are given that 85% of the total of 500 students in the school are the boys. We have to find the number of girls. First of all, let us find the number of boys out of 500 students in school. We get,
\[\text{Number of boys}=\dfrac{\text{Percentage of boys }\times \text{ Total number of students}}{100}\]
We are given that the percentage of boys is equal to 85% and the total number of students is 500. So, we get,
\[\text{Number of boys}=\dfrac{85\times 500}{100}\]
\[=85\times 5\]
= 425 boys
Therefore, the number of boys in the class will be 425.
Now, we know that total students in school consist of boys and girls. So we get,
Total number of students = (Number of boys) + ( Number of girls)
By substituting the value of the total number of students as 500 and the number of boys as 425 in the above equation. We get,
500 = 425 + (Number of girls)
Number of girls = 500 – 425
Number of girls = 75
So, we get the number of girls as 75.

Note: In this question, we can directly find out the number of girls in the school by subtracting the percentage of boys from 100% to get the percentage of girls and then using
\[\text{Number of girls}=\dfrac{\text{Percentage of girls }\times \text{ Total number of students}}{100}\]
Percentage of girls = 100 % - percentage of boys
Percentage of girls = 100 % - 85 % = 15 %
\[\text{Number of girls}=\dfrac{15\times 500}{100}=75\text{ girls}\]
This is equal to what we have calculated.