Question

A man completes a journey in 10 hours. He travels first half of the journey at the rate of 21 km/hr and the second half at the rate of 24 km/hr. Find the total journey in km.


Hi guys though I found the ans of the question but still its not clear.

First what does "He travels first half of the journey " means, does it the first half of time or the first half of the distance? please explain ans & how you reached the conclusion.

Second why 5*21 + 5*24 is not the ans . Thank you.

Answer 1

Answer:

Step-by-step explanation:

25.2 km

Multiply the 21×24=2,520

Then multiply with 10 it will 25,200km/hr

Then calcut in km

Answer 2

Answer:

Step-by-step explanation.

let the journey be of x km .

thus, first half of journey is x/2 km which is half of total journey in km.

time=distance/speed

thus, x/2 / 21 is the time for first half of journey and x/2 / 24 is the time for second half fof journey.

time for first half + time for second half = total time

x/2 /21 + x/2 /24 = 10

x/42 + x/48 =10

15x=3360

x=224

5*21+5*24 is not the answer because half journey means half the distance not half the time