If Columbus rows 20 km upstream in 4 hours and 21 km downstream in 3 hours,…

Step-by-Step Solution

To find the speed of the stream, we first determine the upstream and downstream rates.

1. Calculate the speeds:

   • Upstream speed (rate) = 20 km / 4 hours = 5 kmph.

   • Downstream speed (rate) = 21 km / 3 hours = 7 kmph.

2. Calculate the stream speed:

   • The speed of the stream is equal to half the difference between the downstream and upstream speeds.

   • Speed of stream = (Downstream speed - Upstream speed) / 2

   • Speed of stream = (7 kmph - 5 kmph) / 2

   • Speed of stream = 2 / 2 = 1 kmph.