Question

When you add 18 to 1/4 of a number you get the number itself

Answer 1

X - the number

$\frac{1}{4}x+18=x \\ 18=x-\frac{1}{4}x \\ 18=\frac{3}{4}x \ \ \ |\times \frac{4}{3} \\ 18 \times \frac{4}{3} = x \\ 6 \times 4=x \\ x=24$

The number is 24.