It is always best to solve these problem by writing a linear equation in one variable. Two variables may need to be written if two unknown ages are not related by a fact.

Questions involving ratios should also be first rewritten with a variable. For example, Ages of husband and wife are in a ratio 4:3 then the ages can be rewritten as 4x and 3x

Always ensure that multiplier are put on the correct side of the equation. For example, Father's age is 4 times the son's age then if son's age is x Father's age will be 4x and not viceversa

If there are more than one conditions in the question build your equation step by step to incorporate all the given information. Very rarely any piece mentioned is useless

If you cannot calculate the answer the correct option is "Data Inadequate" or "Cannot be Determined". If you found an answer not listed in the answer option the choice would be "None of these"