In a family, a couple has a son and a daughter. The age of the father is four times that of his daughter and the age of the mother is three times of his son. The husband is twelve years older to his wife and the sister is six years younger than her brother. What is the age of the sister?
Let daughters age = x years And let son’s age = y years ∴ Father’s age = 4x years Mother’s age = 3 y years ∴ 4x – 3y = 12 -------- (1) y – x = 6 -------------- (2) By solving both the equations 1 and 2, we get y = 36 By putting value of in equation (2) we will get sister’s age ∴ Sister’s age = 36 - x = 6 ∴ x = 30 years