Question : Rajinder drives his car at an average speed of 40 km/hr to cover half of his total distance and thereafter he increases his speed to 60 km/hr. He covers his journey in 7 hours. What is the average speed of Rajinder on this journey?

Option 1: 52 km/hr

Option 2: 48 km/hr

Option 3: 50 km/hr

Option 4: 54 km/hr

Question : One-third part of a certain journey is covered at the speed of 10 km/hr, one-fourth part at the speed of 15 km/hr, and the rest part at the speed of 20 km/hr. What will be the average speed (in km/hr) for the whole journey?

Option 1: $15$

Option 2: $\frac{200}{17}$

Option 3: $\frac{240}{17}$

Option 4: $\frac{280}{17}$

Question : A car covers the first 210 km at a speed of 70 km/h, it covers the next 170 km at a speed of 85 km/h. What is its average speed?

Option 1: 72 km/h

Option 2: 76 km/h

Option 3: 74 km/h

Option 4: 68 km/h

Question : A man makes four trips of equal distances. His speed on the first trip was 720 km/hr and in each subsequent trip, his speed was half of the previous trip. What is the average speed of the man in these four trips?

Option 1: 104 km/hr

Option 2: 156 km/hr

Option 3: 192 km/hr

Option 4: 288 km/hr

Question : A train runs from Howrah to Bandel at an average speed of 20 km/h and returns at an average speed of 30 km/h. The average speed (in km/h) of the train in the whole journey is:

Option 1: 20

Option 2: 22.5

Option 3: 24

Option 4: 25