Multiple choice

A speeding car travelling at $40 km/hr$ decides to slow down to $30 km/hr$ after covering half the distance. What is the average speed?

  1. $34.29 km/h$
  2. $35.36 km/h$
  3. $36.32 km/h$
  4. $33.24 km/h$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Average speed = 2 * v1 * v2 / (v1 + v2) = 2 * 40 * 30 / (40 + 30) = 2400 / 70 = 34.2857 km/h.

AI explanation

The average speed for equal distances traveled at two different speeds is found using the formula 2xy / (x + y). Substituting the initial and final speeds of 40 km/hr and 30 km/hr gives (2 * 40 * 30) / (40 + 30). The calculation 2400 / 70 results in an average speed of approximately 34.29 km/h.

Keep practicing — related questions