A student reaches the bus station at speed of 8 km/hr on the cycle, boards the bus to the B point whose speed is 15 km/hr. From B to the rickshaw stand he gets a lift from the bike which travels at speed of 20 km/hr. From the rickshaw stand to the exam center he travels at speed of 12 km/hr. If the distance between home to the bus station, bus station to B, B to rickshaw stand, Rickshaw stand to exam center is equal then find student’s average speed. (Approximate values whenever felt necessary)

A student reaches the bus station at speed of 8 km/hr on the cycle, boards the bus to the B point whose speed is 15 km/hr. From B to the rickshaw stand he gets a lift from the bike which travels at speed of 20 km/hr. From the rickshaw stand to the exam center he travels at speed of 12 km/hr. If the distance between home to the bus station, bus station to B, B to rickshaw stand, Rickshaw stand to exam center is equal then find student’s average speed. (Approximate values whenever felt necessary) Correct Answer 12 km/hr

Given:

Speed through cycle = 8 kmph

Speed through bus = 15 kmph

Speed through bike = 20 kmph

Speed  through rickshaw = 12 kmph

Formula used:

Speed = Distance/Time

Calculation:

LCM of 4 speeds = LCM (8, 12, 15, 20)

⇒ 4 × 2 × 5 × 3 = 120

⇒ Total distance covered = 120 × 4

⇒ Total distance covered = 480 km

⇒ Time taken to travel from home to bus station = 120/8

⇒ Time taken 1 = 15 hours

⇒ Time taken to travel from bus station to B = 120/15

⇒ Time taken 2 = 8 hours

⇒ Time taken to travel on bike = 120/20

⇒ Time taken to travel on bike = 6 hours

⇒ Time taken to travel on rickshaw = 120/12

⇒ Time taken to travel on rickshaw = 10 hours

⇒ Average speed = (Total distance/4)/(Total time/4)  (∵ average speed = average distance/average time)

⇒ Avg. Speed = 480/(15 + 8 + 6 + 10)

⇒ Avg. Speed = 480/39

⇒ 480/39 ≈ 12 km/hr

∴ Required answer is 12 km/hr.

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.