There is a 120 litre mixture of vinegar and water. The ratio of vinegar to water is 7: 5. A shopkeeper mixes a certain amount of water in order to make the ratio of vinegar to water 5: 6. Then find the new quantity of water is what percentage of original quantity of water in the mixture?

Original mixture 120L with vinegar:water = 7:5. Water = 5/12 × 120 = 50L. After adding x liters water, new ratio vinegar:water = 5:6. Vinegar is still 70L. So 70/(50+x) = 5/6, giving 420 = 250 + 5x, so 5x = 170, x = 34L. New water quantity = 50 + 34 = 84L. Percentage of original water = 84/50 × 100 = 168%. Option B is correct.