## 266. Math Puzzle $7 / 87$

Berliners are known for being clever contemporaries. So when asked what time it was, Mariechen from Prenzlauer Berg replied snappily: "Until the end of the day, twice two fifths of the time that has already elapsed since its beginning remain." What time was it at that moment?
The day has 1440 minutes. If the time elapsed since midnight is denoted by $x$, the remaining time until midnight is twice two fifths, or four fifths, of the minutes already completed:

$$
x+\frac{4}{5} x=1440 \quad ; \quad x=800
$$

800 minutes have passed since the start of the day. Therefore, it is currently 13:20.