KurilooStudy·Practice·Succeed
Aptitude Topics

Ages Problems

Age problems involve tracking ratios that change across past, present, and future timelines while the absolute difference between ages stays the same.

Fundamental Principles

Timeline Invariance

The mathematical fact that the age difference between two people never changes, no matter how many years pass into the past or future.

Essential Formulation Tips

  • When adding or subtracting years to shift a timeline, remember to apply the change to both people's ages.
  • Clearly label your algebraic variables to separate past ratios, present ratios, and future ratios.

Shortcut Execution Techniques

  • If the ratio of ages changes from 2 : 3 to 3 : 4 over a span of 5 years, notice that both ratio parts increase by exactly 1 unit. This means 1 ratio unit equals 5 years.

Contextual Inquiries (FAQs)

Q: Why can't we just cross-multiply ratios from different years directly?

A: Because adding a fixed number of years changes the value of the ratio itself, even though the absolute difference between the ages stays the same.