Solution - Word Problem

2 sentences contain the information we are after.

The first, [The sum of the 2 numbers is 15], we learn that:

There are 2 numbers we are looking for, as we don't know what they are, we will refer to them as $$x$$ and $$y$$.

The sum of $$x$$ and $$y$$ is 15. This can be mathematically expressed as $$x+y=15$$

From the following sentence, [the quotient of the 2 numbers is 4], we further learn that the quotient of $$x$$ and $$y$$ equals 4.

This information, can then be expressed in another equation, which would be $$\frac{x}{y}=4$$

We now have a system of equations:

$$x+y=15$$
$$\frac{x}{y}=4$$