58. 729 ml of mixture
contains milk and water in the ratio 7 : 2. How much more water is to be added
to get a new mixture containing milk and water in the ratio 7 : 3 . [Railways
1992]
79 ml 72 ml
81 ml 91 ml
Answer: 81 ml
Explanation: 729 * 7/9 = 567 ml, Water = 729 -
567 = 162
Let water added is x ml
567/(162 + x) = 7/3 or 1701 = 1134 + 7x or x = 81 ml
