Explanation: In this problem, we are asked to calculate the total distance covered by a person traveling from Lucknow to Bhopal and then returning back to Lucknow. The distance between Lucknow and Bhopal is given as 686 km.
The concept of a round trip is central to solving this problem. A round trip involves traveling from one point to another and then returning to the starting point. Therefore, the total distance covered in a round trip is twice the one-way distance.
To find the total distance covered in the round trip, we need to multiply the one-way distance by 2. The one-way distance from Lucknow to Bhopal is 686 km. Therefore, the total distance covered in the round trip is:
\[ \text{Total Distance} = 2 \times \text{One-Way Distance} \]
\[ \text{Total Distance} = 2 \times 686 \, \text{km} \]
\[ \text{Total Distance} = 1,372 \, \text{km} \]
Thus, the correct answer is 1,372 km.
It is important to understand that the total distance covered in a round trip is always twice the one-way distance. This concept is widely applicable in various scenarios involving travel and transportation, and it is a fundamental principle in distance and travel calculations.
Common mistakes students make include forgetting to double the one-way distance or confusing the one-way distance with the total round trip distance. To avoid these mistakes, it is crucial to remember that a round trip involves traveling to a destination and then returning, which means the total distance is twice the one-way distance.
In summary, the total distance covered in a round trip from Lucknow to Bhopal and back is 1,372 km, which is twice the one-way distance of 686 km.