The problem asks: $16$ is what percent of $40$? The answer should be given with a percent sign (%).

1. Problem Description

The problem asks: $16$ is what percent of $40$? The answer should be given with a percent sign (%).

2. Solution Steps

Let $x$ be the percentage we are looking for.

We can set up the equation:

$16 = x \times 40 / 100$

This can be written as

$16 = (x/100) \times 40$.

To solve for $x$, we can divide both sides of the equation by 40:

$16/40 = x/100$

Simplify the left side:

$2/5 = x/100$

Multiply both sides by 100:

$(2/5) \times 100 = x$

$x = 200/5$

$x = 40$

Therefore, $16$ is $40\%$ of $40$.

3. Final Answer

40%