A bus covers a distance of 30 km in 45 minutes and further it covers double the distance covered earlier in 60 minutes. The average speed of the bus is ______ km/hr (rounded off to two decimal places).

Correct option is A

Given:
First distance = 30 km, Time = 45 minutes
Second distance = 2 × 30 = 60 km, Time = 60 minutes
Formula Used:
Average speed = Total distance ÷ Total time
1 hour = 60 minutes
Solution:
Total distance = 30 + 60 = 90 km
Total time = 45 + 60 = 105 minutes =$$\frac {105} { 60}$$​= 1.75 hours
Average speed = $$\frac{90 }{ 1.75}$$​ = 51.43 km/hr