1) Cement Mortar is being prepared by mixing cement to sand in the ratio of 1:6 by volume. In a cement mortar of 42 units of volume , how much more cement needs to be added to enrich the mortar to the ratio 2:9?
2) In a solution of common salt in water, the ratio of salt to water was 30:70 as per weight. If we evaporate 100gms of water from one kg of this solution, what will be the ratio of the salt to water by weight?
