Number System
The sum of the ages of a son and father is 65 years. After 5 years the age of father will be double of the age of son. What is the age of son ?
Let the age of the son be x and the age of the father be y.Therefore, x + y = 65 ..........(i)or, 2 x (x + 5) = (y + 5)or, 2x + 10 = y + 5or, 2x - y = 5 ...................(ii)From equations (i) and (ii), x = 20, y = 45
In 150 litre, milk is 84%ie 150 x 84/100 = 126 litre Let us add x litres of waterTherefore, the quantity of mixture = 150 + x∴ 52.5% of (150 + x) = 126 litres 150 + x = 126x100/52.5 = 240 litres∴ x = 240 - 150 = 90 litres