‘A’ rides a cycle at an average speed of 30 km/h and reaches the destination in 6 hours. B covers the same distance in 4 hours. If A increases the average speed by 10 km/h and B increases the average speed by 5 km/h, what would be the difference in their time taken to reach the destination?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 54 min
Both cover the same distance, which is found from A’s first ride; each new time is then distance ÷ new speed.
Distance \(=30\times6=180\) km
B’s speed \(=180\div4=45\) km/h
A’s new speed is 40 km/h, so A takes \(180\div40=4.5\) h
B’s new speed is 50 km/h, so B takes \(180\div50=3.6\) h
Difference \(=4.5-3.6=0.9\) h \(=0.9\times60=54\) min