Question:
A man travelling at a speed of 20 km/hr, reached his office 10 minutes late. Next day he travelled at a speed of 30 km/hr and he reached his office 10 minutes earlier. The distance between his office and home is :
A30 km
B40 km
C50 km
D20 km
Answer:
D. 20 km
Explanation:
When he drives at 20 km/h, it takes (t + 1/6) hours and when at 30 kmph, it takes (t – 1/6) hours. 20 * (t + 1/6) = 30 * (t – 1/6) t = 50 mins=5/6 hrs Distance = 20 * (1) = 20 kms