Question

In a certain school, $20$% of students are below $8$ years of age. The number of students above $8$ years of age is $2/3$ of the number of students of $8$ years age which is $48$. what is the total number of students in the school?

• A. 72
• B. 80
• C. 100
• D. 150

Answer 1

Answer: (C)

100

let the total number of students be $x$.

Given that $20\%$ of students are below $8$ years of age.

Then the number of students above or equal the $8$ years of age $=80\%$ of $x⟶\left(1\right)$

Given that number of students of $8$ years of age $=48⟶\left(2\right)$

Given that number of students above $8$ years of age $=\frac{2}{3}$ of number of students of $8$ years of age.

$⟹$ NUmber of students above of age $8=\frac{2}{3}\times 48=32⟶\left(3\right)$

From equation $\left(1\right)$, equation $\left(2\right)$ and equation $\left(3\right)$

$80\%$ of $x$ $=48+32=80$

$⟹\frac{80x}{100}=80x=100$