In this article, we will discuss the speed formulas and time and distance aptitude questions. As this topic forms an integral part of every competitive exam, you cannot afford to miss this topic. This article will equip you to solve all time, speed and distance word problems.

- Average speed =
**Total Distance covered/ Total Time Taken** - When the distance is constant:
**Average****speed = 2xy/x+****y**; Where, x and y are the two speeds at which the same distance has been covered. - When time taken is constant:
**Average****speed = (x + y)/****2;**Where, x and y are the two speeds at which we traveled for the same time.

**Distance = Speed × Time.**Using this formula, all basic problems can be handled. However, you need to make sure about the correct usage of units while using the above formulas.- Speed is inversely proportional to the time taken when distance travelled is constant. So
**when speed increases, time decreases**and vice versa.

- Relative speed is defined as the speed of a moving object with respect to another. When two objects are moving in the same direction, relative speed is calculated as their difference. When the two objects are moving in opposite directions, relative speed is computed by adding the two speeds.

Let us go through a few solved examples to understand the application of concepts and formulae on Average Speed explained above:

Average Speed: 2xy/(x+y) where, x is the speed while going from A to B and y is the speed while coming back.

So using this formula, we get the answer as **48 kmph.**

Must Read Time, Speed and Distance Articles

- Time, Speed and Distance: Basic concepts
- Time, Speed and Distance- Basics
- Time, Speed and Distance: Problems on Trains

Let the required distance = D km. As time taken at the speed of 50 kmph is more than time taken at 60 kmph, so equation can be formed as D/50-D/60=15/60.Solving this equation, we get the answer as **75 km.**
###### Practice Question:

**Question:** Two trains NaMo Express and RaGa Express start towards each other from two cities,1800 m apart @50kmph and 58 Kmph respectively. As they start, a bird, named Democracy sitting at the front end of RaGa start flying towards NaMo, touches NaMo and then returns to RaGa and so on, until the trains meet. What distance did the bird travel in total if it was flying at the speed of 324 kmph ?
**Answer: **5400 m
###### Time, Speed and Distance: Key Learnings

**For clarification or doubts related to Average Speed and TSD, please post them in the comments section below**

Now, try to solve the following question using the concept learnt above:

Suggested Action:

- While the question statement can be varied, the basic formula for TSD (time, speed and distance) remains the same, and that forms the core to handle any question from this critical topic.
- Also, we learnt some shortcut formulae to calculate average speed (in cases of constant distance and time) which can be used to arrive at the correct answer in a matter of seconds!