Upstream-Downstream relative speed question
- September 24, 2015
- Posted by: Kamal Rawat
- Category: Quantitative Aptitude
A person rides a cycle at a constant speed.
When he drives in the direction of the wind, he is able to go 35 km in 5 hrs. While returning, when the wind was against the direction of his driving, he took 7hrs for the same distance.
At what speed does he rides when there is no wind?
Let speed of cycle = x km/hr.
Let speed of wind = y km/hr.
we know the formulas, Let’s revise them:
While riding in the direction of the wind, speed = x + y
While riding in the opposite direction of the wind, speed = x + y
35 = (x + y) * 5
35 = (x – y) * 7
Elaborating the equations, we get
5.x + 5.y = 35
7.x – 7.y = 35
Solving the above equations:
x = 6, y = 1
Speed of cycle = 6 km/hr.
Speed of Wind = 1 km/hr.