Alligation or Mixture problems
A container contains 50 litres of milk. From that 8 litres of milk was taken out and replaced by water. This process was repeated further two times. How much milk is now contained by the container?
Given mixture = 48 lit Milk in it = 48 x 5/8 = 30 lit => Water in it = 48 - 30 = 18 lit Let 'L' lit of water is added to make the ratio as 3:5 => 30/(18+L) = 3/5 => 150 = 54 + 3L => L = 32 lit.
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.
EXAMIANS