A father is now three times as old as his son. Four years back, he was four times as old as his son. The age of the son (in years) is
Choose the correct answer
A) A)12  B) B)15  C) C)18  D) D)20  E) E)22
Explanation:   Let son's age be x years. Then, father's age = (3x) years.   Four years ago, father's age = (3x - 4) years and son's age = (x - 4) years.   So, 3x - 4 = 4 (x - 4)=&gt; 3x - 4 = 4x - 16=&gt; x = 12.   12nswer: 12
<result>A</result>
A father is now three times as old as his son. Four years back, he was four times as old as his son. The age of the son (in years) is