The ratio of alcohol to water in two containers, $A$ and $B$, are $5:3$ and $1:3$, respectively, with both containers having infinite capacity. Suppose that the aim is to obtain $2.1$ litre of liquid which is composed of equal quantities of alcohol and water. How much liquid should be drawn from $A$?

The ratio of alcohol to water in a vessel of capacity 80 litres is 5:3, and two draws of 20 litres each are planned. After the $1^{st}$ draw, 20 litres of water are poured into the vessel, mixed well, and then the $2^{nd}$ draw ensues. The liquid drawn in 2 lots is also mixed well in another vessel. What's the ratio of alcohol to water in this second vessel?