Kamal runs 240 meters every day and increases his run to 400 meters on each Saturday. Over a continuous period of four weeks, how many kilometers does he run in total?

Introduction / Context:
This question is a basic time and distance problem that checks whether a student can convert meters into kilometers and correctly account for different distances run on different days of the week. Such questions are very common in aptitude and competitive exams to test comfort with unit conversion and simple arithmetic over multiple days.

Given Data / Assumptions:

• Kamal runs 240 meters every day from Sunday to Friday.
• On every Saturday, he runs 400 meters instead of 240 meters.
• We consider a continuous period of four weeks, which is 4 * 7 = 28 days.
• There are exactly four Saturdays in these four weeks.
• We need the total distance in kilometers.

Concept / Approach:
The key idea is to separate the days into two groups: ordinary days with 240 meters and Saturdays with 400 meters. We multiply the daily distance by the number of corresponding days, add the results to get the total distance in meters, and finally convert meters into kilometers using the relation 1000 meters = 1 kilometer. This direct approach avoids any unnecessary complexity and is ideal for quick calculations in an exam setting.

Step-by-Step Solution:
Number of weeks = 4 Total days = 4 * 7 = 28 days Number of Saturdays in four weeks = 4 Number of non-Saturday days = 28 - 4 = 24 days Distance on each non-Saturday day = 240 meters Distance on each Saturday = 400 meters Total distance on non-Saturdays = 24 * 240 = 5760 meters Total distance on Saturdays = 4 * 400 = 1600 meters Total distance in meters = 5760 + 1600 = 7360 meters Convert to kilometers: distance in km = 7360 / 1000 = 7.36 km

Verification / Alternative check:
A quick mental check is useful. If Kamal ran 240 meters every day for 28 days, that would be 28 * 240 = 6720 meters. Because he actually runs an extra (400 - 240) = 160 meters on each of the four Saturdays, the additional distance is 4 * 160 = 640 meters. So the true total is 6720 + 640 = 7360 meters, which again converts to 7.36 kilometers, confirming our earlier calculation.

Why Other Options Are Wrong:
5.75 km underestimates the total distance and ignores either some days or the extra Saturday distance. 8.20 km and 6.98 km are overestimates or underestimates that do not match the exact multiplication and addition described above. The value 7.04 km is close but still incorrect because it does not correspond to any correct combination of 240 meter and 400 meter runs over four weeks.

Common Pitfalls:
Students often make two common mistakes: forgetting that four weeks contain four Saturdays, and mixing up meters and kilometers by not dividing by 1000 correctly. Another typical error is assuming that Kamal runs 240 meters plus 400 meters on Saturdays, instead of only 400 meters. Carefully reading the wording and systematically separating ordinary days and Saturdays helps avoid these issues.

Final Answer:
The total distance Kamal runs over four weeks is 7.36 km.