Question

A man has to be at a certain place at a certain time. He finds that he shall be 20
minutes late if he walks at 3 km/h speed and 10 minutes earlier if he walks at a speed
of 4 km/h_The distance he has to walk is
w​

Answer 1

Answer:

A man has to be at a certain place at a certain time. He finds that he shall be 20 minutes late if he walks at 3 km/hour speed and 10 minutes earlier if he walks at a speed of 4 km/hour.what The distance he has to walk is?

2 Answers



Gargi Joshi

Answered April 12, 2021

let total distance be s,

v1=3km/h

t1= t+20 min=(t+1/3)h

v2= 4km/h

t2=t-10min=(t-1/6)h

s=v1t1= 3(t+1/3)

=3t+3/3

s=(3t+1)……………. (1)

s=v2t2= 4(t-1/6)

=4t-4/6

s=(12t-1)/3………..(2)

from (1) and (2)

3t+1=(12t-1)/3

[by cross multiplication]

9t+3=12t-1

t=4/3 h

substituting t in (1)

s=3t+1=3(4/3)+1=4+1

s=5km {ans.}