20% of what number is 18

To find 20% of a number, you can divide that number by 100 and then multiply by 20.

Let's denote the number as x.
So, (20/100) * x = 18

To solve this equation for x, we can multiply both sides by 100/20:
x = (18 * 100) / 20

Simplifying the expression, we get:
x = 90

Therefore, 20% of 90 is equal to 18.