The sales agent needs to cover 50 km in less time. The distance remains the same at 50 km.
Original time = 2 hours 30 minutes = 2.5 hours
Time reduction = 5/6 hours (approximately 0.833 hours)
Original Speed = Distance ÷ Time
Original Speed = 50÷2.5
Original Speed = 20 km/h
New Time = Original Time - Time Reduction
New Time = 2.5−65
New Time = 1.66 hours (or 5/3 hours)
New Speed = Distance ÷ New Time
New Speed = 50÷(5/3)
New Speed = 30 km/h
Increase in Speed = New Speed - Original Speed
Increase in Speed = 30−20
Increase in Speed = 10 km/h
Therefore, the agent must travel 10 km/h faster on average.