Class 7 Maths Algebric Expressions QA
Class 7 Algebric Expressions Question 1: The sum of the ages of a father and his son is 48 years. After 12 years, the father's age will be twice the age of his son. Find their present ages. Solution: x + y = 48 ...(1) x + 12 = 2(y + 12) x + 12 = 2y + 24 x = 2y + 12 ...(2) Put equation (2) in equation (1). 2y + 12 + y = 48 3y + 12 = 48 3y = 36 y = 12 years x = 48 - 12 x = 36 years Answer: Father = 36 years, Son = 12 years. Question 2: The sum of the ages of a mother and her daughter is 42 years. After 5 years, the mother's age will be three times the age of her daughter. Find their present ages. Solution: x + y = 42 ...(1) x + 5 = 3(y + 5) x + 5 = 3y + 15 x = 3y + 10 ...(2) Put equation (2) in equation (1). 3y + 10 + y = 42 4y + 10 = 42 4y = 32 y = 8 years x = 42 - 8 x = 34 years Answer: Mother = 34 years, Daughter = 8 years. Question 3 The sum of the ages of two brothers is 24 years. The elder brother is twice as old as the younger brother. Find their present ages. Solution: Le...