4 31/40 + 15

To find the answer, just add the whole numbers.

$${\mathtt{4}}{\mathtt{\,\small\textbf+\,}}{\mathtt{15}} = {\mathtt{19}}$$

Now, combine the fraction and the whole number.

$$19\dfrac{31}{40}$$

So, $$19\dfrac{31}{40}$$ is the answer.