If Tanmay covers three equal distances at the speeds of 2 km/h, 3 km/h and 4 km/h, respectively, then find his average speed (in km/h) during the whole journey. (Rounded off to 2 decimal places)
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 2.77.
Let the total distance be 12 km
Time taken by 2 km/hr = 12/2 = 6 hr
Time taken by 3 km/hr = 12/3 = 4 hr
Time taken by 4 km/hr = 12/4 = 3 hr
Total time = 6 + 4 + 3 = 13 hours
Total distance = 12 × 3 = 36 km
Speed = 36/13 = 2.77 km/hr