A man cycles to a village at 18km/h and returns at 12km/h. If he takes 25/4 hours for the double journey, how far does he ride altogether
Let the distance to the village be x km.
Time taken to cycle to the village = x/18 hours
Time taken to cycle back from the village = x/12 hours
Total time taken for the double journey = x/18 + x/12 = (2x + 3x)/36 = 5x/36 hours
Given that the total time taken for the double journey is 25/4 hours, we have 5x/36 = 25/4.
Multiplying both sides of the equation by 36, we get 5x = 225.
Dividing both sides of the equation by 5, we get x = 45.
Therefore, the man rides a total distance of 45 km. Answer: \boxed{45}.