Rahul and his friends left for Guptipara by bus at 3 p.m. The bus trav

1.	Rahul and his friends left for Guptipara by bus at 3 p.m. The bus travelled at an average speed of 45 km/h for the first hour and then the group took a break for 30 minutes. After the break,the bus travelled at 30 km/h for only 15 minutes when it had to stop because of a punctured tyre.After getting the tyre repaired, the bus travelled at 50 km/h to finally reach Guptipara at 6.45 p.m.What was the average speed of the bus in completingthe journey of 90 km?
Answer» ANSWER: Average SPEED = Total distance covered/Total TIME taken $= \frac{90km}{6.45p.m. - 3p.m.} = \frac{90km}{3h \: 45min}$ Now, $\frac{45min}{1hour} = \frac{45min}{60min} = 0.75hours$ THUS, Average speed $= \frac{90km}{3.75h} = 24km \: per \: hour$