In an examination, 96% of students passed and 500 students failed. How many students did appear at the examination ?

Let number of students who appeared at the examination be $$x$$
Passed percentage = 96%
Failed percentage = 4%
According to given information we get
Unsuccessful students = 4%
∴ 4% of $$x$$ = 500
⇒ $$\left( {\frac{{x \times 4}}{{100}}} \right)$$  = 500
⇒ $$x$$ = $$\left( {\frac{{500 \times 100}}{{4}}} \right)$$
⇒ $$x$$ = 12500