Question

In a journey of 80km, a train covers the first 60 km at 40km/h and the remaining at 20km/h. How would one calculate the average speed of the whole journey?

Answer 1

Hey mate your answer goes like this

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First let us write the given data.

Total distance to cover = 80km.

Distance covered with speed 40 km/h = 60 km

Distance covered with speed 20 km/h = 20 km (80–60=20)

Formulae used :

Speed= distance /time, time = distance /speed

Average speed = total distance /total time

Solution :

Time required to cover first 60 km with speed 40km/h=60/40=1.5 hours

Time required to cover remaining distance with speed 20km/h=20/20=1 hour

Total time of journey = 2.5 hours

Average speed = 80/2.5= 32 km/h

HOPE IT HELPS!!

✌️✌️✌️✌️✌️✌️✌️✌️✌️

Answer 2

hey bro here is ur answer

TOTAL DISTANCE = 80 KM ..

for first 60 km ....it's speed is 40 km/h

it means that time = distance /speed

so time for 1st 60 km is .. 60/40 =3/2 hrs.

next remaining distance = 80-60 = 20

speed = 20 km/h so time = 20/20= 1 hr.

TOTAL TIME = 3/2+1 = (3+2)/2 = 5/2 HRS..

total distance = 80km ..

so avg. speed = total distance / total time

= 80/(5/2) = 80×2)/5 = 16×2 = 32 km/h

hope it's help u❤️❤️❤️