A student goes to his school from his house walking at 4 km/h and reaches his school 10 min late. Next day, starting at the same time he walks as 6 km/h and reaches his school 5 min earlier than the scheduled time. Find the distance between school and home?
Correct Answer: 3 km
Explanation:
Let the distance be x km.
∴ Time = Distance/speed
1st day time taken = x/4 h
2nd day time taken = x/6 h
Difference in time = (x/4 - x/6) h
Actual difference between these two times = 15 min = 1/4 h
∴ x/4 - x/6 = 1/4 ⇒ (3x - 2x)/12 = 1/4
∴ x = 3 km
