Multiple choice

Ram rows a boat at a speed of $15$ kmph upstream and $20$ kmph downstream. Find the speed with which he rows the boat in still water

  1. $\dfrac {5}{2}$
  2. $\dfrac {15}{2}$
  3. $10$
  4. $\dfrac {35}{2}$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Speed in still water = (Downstream speed + Upstream speed) / 2. (20 + 15) / 2 = 35 / 2.

AI explanation

Using the formula for speed in still water, we calculate the average of the upstream and downstream speeds. Substituting the given values gives (15 + 20) / 2. This equals 35/2. The result is 35/2.

Keep practicing — related questions