23. Container A contains 2 liters of sulfuric acid solution with a concentration of $30 \%$, and container B contains 3 liters of sulfuric acid solution with a concentration of $10 \%$. Now, sulfuric acid solutions with concentrations of $6 \%$ and $22 \%$ are being added to containers A and B, respectively, at rates of 0.1 liters per minute and 0.3 liters per minute. After $\qquad$ minutes, the concentrations of the sulfuric acid solutions in containers A and B will be equal.
$20$