Half of the total journey is covered at the speed of 90 km/hr, while 1/3 of total journey is covered at the speed of 75 km/hr and 1/6 of total journey is covered at the rate of 50 km/hr. Find the average speed of the whole journey in m/s if distance of total journey is 900 km.

Half of the total journey is covered at the speed of 90 km/hr, while 1/3 of total journey is covered at the speed of 75 km/hr and 1/6 of total journey is covered at the rate of 50 km/hr. Find the average speed of the whole journey in m/s if distance of total journey is 900 km. Correct Answer <span style=" line-height: 115%; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;">125/6 m/s</span>

Given:

Total journey = 900 km

Half of total journey is covered at the speed of 90 km/hr

1/3 of total journey is covered at the rate of 75 km/hr

1/6 of total journey is covered at the rate of 50 km/hr

Concept used:

Average speed = Total Distance/Total time taken

Speed in m/s = speed in km/hr × 5/18

Calculation:

Total journey = 900 km

Half of the total journey = 450 km

⇒ 450 km is covered at the rate of 90 km/hr

⇒ Time taken to cover 450 km = 450/90 = 5 hours

Now, 1/3 of total journey = 300 km

⇒ 300 km is covered at the rate of 75 km/hr

⇒ Time taken to cover 300 km = 300/75 = 4 hours

Now, 1/6 of the total journey = 150 km

⇒ 150 km is covered at the rate of 50 km/hr

⇒ Time taken to cover 150 km = 3 hours

Now, Total time taken to cover whole journey = (5 + 4 + 3) hours

⇒ Total time taken = 12 hours

Average speed of the whole journey = 900/12

⇒ Average speed of the whole journey = 75 km/hr

 Speed in m/s = speed in km/hr × 5/18

⇒ As we know, Speed in m/s = speed in km/hr × 5/18

⇒ Speed in m/s = 75 × 5/18

⇒ 125/6 m/s

Related Questions

Each of the question below consists of a question and three statements number I, II and III given below it. You have to decide whether the data provided in the statement are sufficient to answer the question. If the bus is travelling from Surat to Ahmadabad and a car is travelling from Ahmadabad to Surat, then what is the distance between Surat and Ahmadabad? I. The speed of a car is 40% less than the speed of bus. Bus started at 9 am and car started at 10 am and they meet at 3 pm of the same day. II. After travelling for 1 hour, because of traffic average speed of bus is decreased by 20% and covers distance between Surat to Ahmadabad in 11 hours. Original speed of car is 20% less than original speed of bus and before crossing bus it covered 200 km if starts 1 hour later than bus. After crossing car, bus covers remaining distance in 5 hours. III. Speed of bus is 10 km/hr more than the speed of car and before crossing car ratio of distances covered bus and car in same time was 5 : 4. Time taken by car to cover the distance between Ahmadabad and Surat is 2 hours 15 minutes more than time taken by bus to cover the same distance.