Time Speed Distance Tricks - Average Speed (GMAT/GRE/CAT/Bank PO/SSC CGL) | Don't Memorise

TL;DR

Average speed is calculated by dividing the total distance traveled by the total time taken, and it can be influenced by the amount of time spent at each speed.

Transcript

The distance between points 'A' and 'B' is 8 kilometers. Zen begins at point 'A' and covers half this distance at 2 kilometers per hour. Half the distance would be 4 kilometers. and from this point to B, he travels at 4 kilometers per hour. As the total distance is 8 kilometers, and this is 4 kilometers, this distance will equal 4 kilometers. So he... Read More

Key Insights

• 🐎 Average speed in distance problems is calculated by dividing the total distance traveled by the total time taken.
• 🐎 The average speed can be influenced by the amount of time spent at each speed.
• 🐎 If more time is spent at a lower speed, the average speed will be closer to the lower speed.
• 🚄 Conversely, if more time is spent at a higher speed, the average speed will be closer to the higher speed.
• 🐎 Average speed is not necessarily the same as the speed traveled for the majority of the distance.
• 🐎 It is important to calculate the total distance and total time to accurately determine the average speed.
• 🧑‍🎓 Average speed is a concept often misunderstood by students.

Questions & Answers

Q: How is average speed calculated?

Average speed is calculated by dividing the total distance traveled by the total time taken to travel that distance.

Q: Why is Zen's average speed 3 kilometers per hour when he traveled at both 2 and 4 kilometers per hour?

Zen's average speed is 3 kilometers per hour because he spent more time traveling at 2 kilometers per hour than at 4 kilometers per hour.

Q: Can average speed be closer to one speed than another?

Yes, the average speed can be closer to one speed than another depending on the amount of time spent at each speed.

Q: What factors influence average speed?

The amount of time spent at each speed and the distance traveled at each speed influence the average speed.

Summary & Key Takeaways

• Zen covers half the distance at 2 kilometers per hour and the remaining half at 4 kilometers per hour. His average speed is 3 kilometers per hour.

• Average speed equals the total distance divided by the total time taken to travel that distance.

• The average speed can be closer to one speed than another depending on the amount of time spent at each speed.