729 ml of a mixture contains milk and water in ratio 7:2. How much of the water is to be added to get a new mixture containing half milk and half water?
162
405
81
567
Explanation:
The quantity of milk in the mixture i = 7/(7+2) $\times$ 729 = 7/9 $\times$ 729 = 567mLThe quantity of water then shall be 729 - 567 = 162mL If the final mixture would contain half milk and half water, there must be equal quantity of both. So in order to make up for water, well need to add 567mL - 162mL= 405mL of water
The quantity of milk in the mixture i = 7/(7+2) $\times$ 729 = 7/9 $\times$ 729 = 567mLThe quantity of water then shall be 729 - 567 = 162mL If the final mixture would contain half milk and half water, there must be equal quantity of both. So in order to make up for water, well need to add 567mL - 162mL= 405mL of water