Every morning Lakshmi walks from her village to the block office at 4 km/h and returns the same way by bus at 40 km/h. The two journeys together take her 5 hours 30 minutes. The total distance she covers in a day (in km) is:

If the village is d km from the office, then d/4 + d/40 = 5.5 → 11d/40 = 5.5 → d = 20 km. She covers that distance twice, so the day's travel is 40 km. (20 km is the one-way distance — the question asks for the whole day's travel. Note how lopsided the times are: 5 hours walking against half an hour in the bus.)