a man can row at 5 km/hr in still water. If the velocity of the current is 1 km/hr and it takes him 1 hour to row to a place and come back, how far is the place?

To determine how far the place is, we need to use the given information about the man's rowing speed and the current's velocity. Here is a step-by-step solution:

1. Define Variables:
  - Let \( d \) be the distance to the place.
  - The man's rowing speed in still water is \( 5 \) km/hr.
  - The current's velocity is \( 1 \) km/hr.

2. Calculate Effective Speeds:
  - Speed downstream (with the current): \( 5 + 1 = 6 \) km/hr.
  - Speed upstream (against the current): \( 5 - 1 = 4 \) km/hr.

3. Calculate Time for Each Leg of the Trip:
  - Time to row downstream: \( \frac{d}{6} \) hours.
  - Time to row upstream: \( \frac{d}{4} \) hours.

4. Total Time for the Round Trip:
  The total time taken for the round trip is given as \( 1 \) hour. Therefore:
  \[
  \frac{d}{6} + \frac{d}{4} = 1
  \]

5. **Solve the Equation:**
  To solve this, find a common denominator (which is 12):
  \[
  \frac{d}{6} = \frac{2d}{12}
  \]
  \[
  \frac{d}{4} = \frac{3d}{12}
  \]
  Adding these together:
  \[
  \frac{2d}{12} + \frac{3d}{12} = 1
  \]
  \[
  \frac{5d}{12} = 1
  \]
  Solving for \( d \):
  \[
  5d = 12
  \]
  \[
  d = \frac{12}{5} = 2.4
  \]

Therefore, the place is \( 2.4 \) km away.