KurilooStudy·Practice·Succeed
Aptitude Topics

Train Basics

Problems on trains are an extension of basic Speed, Distance, and Time principles. The core formula remains $Distance = Speed \times Time$, but applying it requires strict attention to matching units and tracking moving references.

Fundamental Principles

Unit Synchronization

Train problems typically express train lengths in meters but speeds in kilometers per hour (km/h). To solve equations accurately, all parameters must be converted to a uniform system—usually meters and meters per second (m/s).

Essential Formulation Tips

  • Always check your units first before setting up an equation. If length is in meters and time is in seconds, your speed must be in m/s.
  • Keep calculations clean by leaving fractions unreduced until the final step, as terms like 18 and 5 frequently cancel out.

Shortcut Execution Techniques

  • The 5/18 Conversion Factor: To convert a speed from km/h to m/s, multiply it by $\frac{5}{18}$. To reverse the conversion from m/s to km/h, multiply by $\frac{18}{5}$.

Contextual Inquiries (FAQs)

Q: Where does the 5/18 conversion factor come from?

A: It is the simplified ratio of meters in a kilometer to seconds in an hour: $\frac{1000 \text{ meters}}{3600 \text{ seconds}} = \frac{10}{36} = \frac{5}{18}$.