Question

girl undertook a journey partly by auto and partly on foot. If she walked at 4kmph and the auto had a speed of 25kmph, she took 42 minutes for the entire journey. What was the distance she covered on foot if her average speed was 10kmph?

Answer 1

Answer:

She covers a distance of 2km on foot.

Step-by-step explanation:

Let the velocity of auto (Va) = 25km/hr

and the velocity on foot (Vb) = 4km/hr

Average velocity= total distance/ total time

therefore, 10 km/hr= S/ 42/60

we divided total time by 60 as it is in minutes and we need to convert it into hour.

Solving this we get total distance as 7 km.

Now, let the distance covered on foot be 'x'.

Vb= X/ t

4= X/t

t= X/4 hr

similarly,

25= (7-x)/ t'

t'= (7-x)/ 25

As we know total time is 42/60 hr.

therefore t+ t' = 42/60

X/4 + (7-x)/25 = 42/60

Solving this we get X= 2km...hence the ans is 2 km...

hope you understand......