## Task 2

Tanja thinks of a number, triples it, and adds 25. Her result is 40. What number did Tanja think of? Set up an equation for this calculation.
$x \cdot 3+25=40$, i.e., the thought number is 5.

### 13.14 25th Olympiad 1987

### 13.14.1 1st Round 1987, Class 4