Alligation or Mixture problems
A jar full of whisky contains 40% alcohol. A part of this whisky is replaced by another containing 19% alcohol and now the percentage of alcohol was found to be 26%. The quantity of whisky replaced is:
By the rule of alligation, we have: Strength of first jar Strength of 2nd jar 40% MeanStrength 26% 19% 7 14 So, ratio of 1st and 2nd quantities = 7 : 14 = 1 : 2 ∴ Required quantity replaced = 2 3
As given equal amounts of alloys are melted, let it be 1 kg. Required ratio of gold and silver = 5 13 + 5 8 8 13 + 3 8 = 105 103 . Hence, ratio of gold and silver in the resulting alloy = 105/103.
Average speed = (100 / 10) = 10 km/hr. Ratio of time taken at 7 km/hr to 12 km/hr = 2 : 3 Time taken at 7 km/hr = 2 (2 + 3) × 10 = 4 hrs. Distance covered at 7 km/hr = 7 × 4 = 28 km. Distance covered at 12 km/hr = 100 ? 28 = 72 km.
Ratio of milk andwater = 4:1 Quantity of water = 35/5 = 7 litres Quantity of milk = 35 X 4/5 = 28 litres If 7 litre of water is added, new quantity of water = 14 litre New ratio of milk and water = 28:14 = 2:1
EXAMIANS