Alligation or Mixture problems
The average age of 6 members of a family is 20 years. If the age of the servant is included, then the average age increase by 25%. What is the age (in years) of the servant?
Ratio of milk and water = 2 : 1Quantity of milk = 60 X 2/3 = 40 litreQuantity of water = 20 litreTo make ratio, 1: 2, we have to double the water that of milkSo, water should be 80 litre.That means 80 ? 20 = 60 litre water to be added.
Average money received by each = 118/50 = Rs. 2.36 Therefore, Ratio of No.of boys and girls = 56 : 24 = 7 : 3 Therefore, Number of boys = 50 x (7/10) = 35 Number of girls = 50 - 35 = 15