passwella.
Menu

JAMB Mathematics 1982 Question 5

Question 5

Linear and Simultaneous Equations

Seven years ago, the age of a father was three times that of his son, but in six years time the age of the son will be half that of the father. Representing the present ages of the father and son by x and y respectively, the two equations relating x and y are

  1. A.3y − x = 0; 2y − x = 0
  2. B.3y − x = 14; x − 2y = 6
  3. C.3y − x = 7; x − 2y = 6
  4. D.3y − x = 14; y − 2x = 6
  5. E.x + 3y = 7; x + 2y = 12.
Show the answer and explanation

Answer: B (3y − x = 14; x − 2y = 6)

Explanation

x − 7 = 3(y − 7) gives 3y − x = 14. In six years, 2(y + 6) = x + 6 gives x − 2y = 6.