The speed of a boat in still water is 6 kmph and the speed of the stream is 1.5 kmph. A man rows to a place at a distance of 22.5 km and comes back to the starting point. The total time taken by him is?Options10 hours6 hours 10 minutes8 hours4 hours 10 minutes

To solve this problem, we need to calculate the time taken to row to the place and back.

1. First, we calculate the effective speed of the boat when it is going downstream (i.e., with the stream). The effective speed is the speed of the boat plus the speed of the stream, which is 6 kmph + 1.5 kmph = 7.5 kmph.

2. Next, we calculate the effective speed of the boat when it is going upstream (i.e., against the stream). The effective speed is the speed of the boat minus the speed of the stream, which is 6 kmph - 1.5 kmph = 4.5 kmph.

3. Now, we calculate the time taken to row to the place and back. The time taken is the total distance divided by the effective speed. The total distance is 22.5 km to the place and 22.5 km back, which is 45 km.

   The time taken to row to the place (downstream) is the distance divided by the effective speed, which is 22.5 km / 7.5 kmph = 3 hours.

   The time taken to row back (upstream) is the distance divided by the effective speed, which is 22.5 km / 4.5 kmph = 5 hours.

4. Finally, we add the time taken to row to the place and the time taken to row back to get the total time taken, which is 3 hours + 5 hours = 8 hours.

So, the total time taken by the man is 8 hours.