## Task 3 - 010933

Find the fraction that equals 0.4, and whose numerator and denominator sum up to a two-digit square number!

How did you find the solution?
Every fraction equal to 0.4 has the form $\frac{2 n}{5 n}$.

The sum $2 n+5 n=7 n$ is only a two-digit square number for $n=7$. Therefore, the sought numerator is 14, and the denominator is 35.