Multiple choice

A boat goes a certain distance at 40 km/hr and comes back the same distance at 24 km/hr. What is the average speed (in km/hr) for the total journey?

  1. 32

  2. 28

  3. 34

  4. 30
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Average speed = (2 * v1 * v2) / (v1 + v2) = (2 * 40 * 24) / (40 + 24) = 1920 / 64 = 30.

AI explanation

Since equal distances are travelled at two different speeds, we use the average speed formula for equal distances: (2 multiplied by speed1 multiplied by speed2) divided by (speed1 + speed2). Substituting the given speeds gives (2 multiplied by 40 multiplied by 24) divided by (40 + 24). Calculating this yields 1920 divided by 64, which equals an average speed of 30 km/hr.

Keep practicing — related questions