Question

a man covered one by third distance at a speed of 25 kilometre per hour and another one by seventh distance at a speed of 40 kilometres per hour on which take speed of 50 kilometres per hour find the average speed when Total distance is 2240km​

Answer 1

Answer:

this is unitary method in the ratio and proportion first find the distance covered in 1 km

Answer 2

Answer: 25

Step-by-step explanation:

1/3 x 2240 = 746.67km at 25km/h

Means time taken = 746.67/25 = 29.8668hrs

1/7 x 2240 = 320km at 40km/h

Means time taken = 320/40 = 8hrs

Rest distance at 50km/h means 1 - 1/3 + 1/7 = 11/21 of total distance

11/21 x 2240 = 1,173.33km at 50km/h

Means time taken = 1173.33/50 = 23.46hrs

So, total time taken = 29.86 + 8 + 23.46 = 61.32hrs

and total distance = 2240km

So, av. speed = 2240/61.32 = 36.529km/h