30 because it is the highest number of marriage
Based on the liquids viscosity (which is a measure of how quickly/slowly a fluid can flow).
Higher viscosity represents a "thicker" liquid & slower flow (honey)
Lower viscosity represents a "thinner" liquid & quicker flow (vinegar)
We determine the percent by mass of water in the compound by dividing the mass of water by the total mass. The total mass of Na2SO4.10H2O is equal to 322 g. The mass of water is 180 g.
percent by mass of water = (180 / 322)*(100 %) = 55.9%
Since the only way of water flow to these lakes or bodies of water is through evaporation, I would expect an increase in unknown substances in the composition of the lakes due to the amount of contamination that globalization produces and affects terribly the surroundings when these unknown substances travel through evaporation as the outlet of these bodies of water. Therefore I think continuous contamination is what to expect after many more years of inflow and evaporation.
Put the mixture in water, the pebbles will sink, the pepper will float, and the sugar will dissolve