FirstHack Learn
Log in Sign up free
Lessons in this course 0/6 All courses Aptitude for Placements

Placements

Progress0 / 6 lessons
  1. 1. Percentages and the shortcuts
  2. 2. Ratio, proportion and partnership
  3. 3. Averages, alligation and mixtures
  4. 4. Time, speed, distance, trains and boats
  5. 5. Time and work with the men-days method
  6. 6. Profit, loss and discount

Courses › Aptitude for Placements

Time, speed, distance, trains and boats

Unit conversion, relative speed, and the two question types that always appear.

15 min read · Lesson 4 of 6 · Pro

One formula, three forms

speed = distance / time, so distance = speed * time and time = distance / speed.

The whole topic is that formula plus careful unit handling.

The conversion you must know cold.

  • km/h to m/s: multiply by 5/18
  • m/s to km/h: multiply by 18/5

So 72 km/h = 72 * 5/18 = 20 m/s. 36 km/h = 10 m/s. Anything divisible by 18 converts in one step.

⚠️

Mixing units is the single biggest source of wrong answers here. Train lengths come in metres and speeds come in km/h. Convert the speed to m/s first, before you do anything else, and write the unit next to every number.

The rest of this lesson is Pro

The free lessons of Aptitude for Placements finish what they start — read those first if you have not. This one goes further, and it is part of the paid half.

A pass opens the paid lessons of every course, the mock test papers and the company-wise series. It ends on its own date; nothing renews by itself.

Get a pass — from ₹29 for 7 days

Already bought one? Log in.