Chapter 1.1B, Problem 15A

One winter night the temperature fell $15$ degrees between midnight and $9$ $\text{A}\text{.M}\text{.}$ By $9$ $\text{A}\text{.M}\text{.}$, the temperature had doubled from what it was at $5$ $\text{A}\text{.M}\text{.}$ By noon, it had risen another $10$ degrees to $32$ degrees. What was the temperature at midnight?