In this article, we will discuss the speed formula 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 Formula
Time and Distance Formula
Relative Speed:
Solved Average Speed problems
Let us go through a few solved examples to understand the application of concepts and formulae on Average Speed explained above:
Example 1:A person goes from A to B at the speed of 40 kmph and comes back at the speed of 60 kmph. What is his average speed for the whole journey?
Solution: Since the distance travelled on both sides is the same, we can use the formula of harmonic mean of speeds
Example 2: Moving at 50 kmph, a person reaches his office 10 min late. Next day, he increases his speed and moves at 60 kmph and reaches his office 5 min early. What is the distance from his home to his office?
Solution: We can observe that difference in timings on both days is 15 min (and not 5 min, as one day he is late and on the other day he is early)
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:
Now, try to solve the following question using the concept learnt above
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 km
Time, Speed and Distance: Key Learnings
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