Problems on Ages
Problems on Ages
Set up algebraic equations from conditions about present, past, and future ages. Exams test ratios, sums, and differences of ages across time points. SSC CGL and IBPS PO papers carry 2\u20134 age questions per paper, making this a high-return topic for minimal preparation time.
Key Idea
Age difference is permanent. If A is 5 years older than B today, A was 5 years older than B 10 years ago too. This single fact unlocks most age problems.
Core Formulas
Age Difference
Age difference is constant — it remains the same regardless of the year
Compare ages at any two time points \u2014 the gap never changes, so subtract it from both sides to isolate the unknown
Ratio Method
Present ages = ak and bk; use condition to find k
Assign variables ak and bk when the question states ages in ratio a:b, then plug into the given condition to solve for k
Past Age
Age n years ago = Present age − n
For questions about past ages
Future Age
Age n years later = Present age + n
For questions about future ages
Average Age
Sum of ages = Average × Count; if one new member joins, new sum = old sum + new age
For group age questions
Relevant Exams
2–4 questions in almost every competitive exam. Age problems appear in both arithmetic and word problem sections. Mastering ratio-based setup solves 80% of questions.