Jayesh covers one-fourth of his journey at 20 km/h, another one-fourth at 10 km/h, and the rest at 70 km/h. What is his average speed?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 22.4 km/h.
Let total distance = 4d km
Total time = d/20 + d/10 + 2d/70 = 5d/28 hours
Average speed = 4d ÷ (5d/28) = 4 × 28/5 = 22.4 km/h