Let the distance covered by car = x km
Distance covered by walk = y km
Speed of car = 25 km/h
Speed of walk = 5 km/h
Hari covered ‘x’ km distance at a speed of 25 km/h and remaining (100 – x) km distance covered at a speed of 5 km/h
⇒ Time taken by Hari
=
+ =
... (i)
Ram covered ‘x’ km distance at a speed of 25 km/h and then he goes back in car a distance of ‘y’ km and picks up Shyam and again travels ‘y’ km to reach the point ‘x’ km and further complete the remaining (100 – x) km journey Ram travels in car = x + y + y + (100 – x)
= 100 + 2y
⇒ Time taken by Ram =
... (ii)
At last Shyam covers (x – y) km distance at a speed of 5 km/h and remaining 100 – (x – 4) in distance at a speed of 25 km/h
⇒ Time taken by Shyam
=
+ =
... (iii)
According to given instruction in question we get,
=
=
⇒ x = 75 and y = 50
Put these value in question (i) then we get that Ram, Shyam and Hari takes 8 hours to complete journey.