A pedestrian and a cyclist start simultaneously towards each other fro...
Given information:
- Distance between Aurangabad and Paithan = 40 km
- They meet 2 hours after the start
- Cyclist arrives at Aurangabad 7 hours 30 minutes earlier than the pedestrian arrives at Paithan
To find:
Which of these could be the speed of the pedestrian?
Let's assume that the speed of the pedestrian is x km/hr and the speed of the cyclist is y km/hr.
Calculation:
- In the first 2 hours, the pedestrian and the cyclist together cover a distance of 2(x+y) km, as they are moving towards each other.
- Therefore, the remaining distance between Aurangabad and Paithan is 40 - 2(x+y) km.
- Let's calculate the time taken by the pedestrian to cover this distance. We know that the cyclist arrives at Aurangabad 7 hours 30 minutes earlier than the pedestrian arrives at Paithan. So, the time taken by the cyclist to cover the distance between Aurangabad and Paithan is (7.5 + t) hours, where t is the time taken by the pedestrian.
- We can write the following equation to find the value of t:
(40 - 2(x+y))/x = t + 7.5
(40 - 2(x+y))/x - t = 7.5
- Now, let's use the equation of speed to find the value of y:
y = (40 - 2(x+y))/(2+t)
- Simplifying the above equation, we get:
y = (40 - 2x - 2y)/(t+2)
y(t+2) = 40 - 2x - 2y
yt + 2y = 40 - 2x
y(t+2) + 2x = 40
- We know that the speed of the cyclist is greater than the speed of the pedestrian, so y > x.
- Let's substitute the value of t in the above equation using the equation we derived earlier:
(40 - 2(x+y))/x - 7.5 = y
40/x - 2 - 2y/x - 7.5 = y
40/x - 2y/x - 9.5 = y
40 - 2y - 9.5x = xy
- We can now substitute the value of y(t+2) + 2x = 40 in the above equation:
(40-2x)/3 - 2y/3 - 9.5x = xy
40 - 6x - 6y - 28.5x = 3xy
40 - 34.5x = 9xy
- Substituting y = (40-2x)/(t+2) in the above equation:
40 - 34.5x = 9x(40-2x)/(t+2)
40(t+2) - 34.5xt - 9x(40-2x) = 0
40t - 5.5xt - x(40-2x) = 0
- We can now substitute the value of t = (40 - 2(x+y))/x - 7.