13.242. Two identical pools started filling with water simultaneously. In the first pool, 30 m$^3$ more water flows in per hour than in the second pool. At some point, the total amount of water in both pools was equal to the volume of each of them. After this, the first pool was filled after 2 hours and 40 minutes, and the second pool was filled after another 3 hours and 20 minutes. How much water flowed into each pool per hour?
Solution.

Let $x+30 \mathrm{~m}^{3} / \mathrm{h}$ be the filling rate of the first pool, $x \mathrm{~m}^{3} / \mathrm{h}$ the second; $V \mathrm{~m}^{3}$ the volume of the pools; $t$ the time when the pools contained $V \mathrm{~m}^{3}$.

According to the problem, $\left\{\begin{array}{l}(x+30) t+x t=V, \\ \left(t+2 \frac{2}{3}\right)(x+30)=V, \\ (t+6) x=V,\end{array}\right.$

from which $x=60$.

Answer: 60 and 90 $\mathrm{m}^{3}$.