A person travels a certain distance at a speed of 18 km/h and returns to the starting point at 12 km/h. If he takes 2 hours 55 minutes for the whole journey, the distance one way is:

21 km

Let distance = D km

\(\frac{D}{18}\) + \(\frac{D}{12}\) = 2\(\frac{11}{12}\)

\(\frac{D}{18}\) + \(\frac{D}{12}\) = \(\frac{35}{12}\)

\(\frac{5D}{36}\) = \(\frac{35}{12}\)

D = 21 km

So , Distance of journey is 21 km