Generally speaking, organic molecules tend to dissolve in solvents that have similar physical properties. A good rule of thumb is that "like dissolves like". Meaning, polar compounds can dissolve polar compounds and nonpolar compounds can dissolve nonpolar compounds.
To apply this to the current problem, we are told that the brushes are being cleaned with vegetable oil or mineral oil. In this case, the oils are used as solvents. In order for these solvents to be effective, the compounds they are trying to dissolve must be similar in structure and properties to other oils. Therefore, vegetable oil or mineral oil will be most effective in removing oil-based paints, as these will have the similar properties needed to dissolve in the oil solvents.
It is rinsed one last time with the solution to be measured because if there is water in the burret, then it could alter the results. Slightly, but it is still altering it.
nose amigo, la verdad yo también tengo dificultades escolares muchísimas gracias, Dios te bendiga en otro idioma por cierto mi anime favorito es cowboy beboop
