Question
What is the average speed of a car which covers half the distance with a speed of 28 km/h and the other half with a speed of 84 km/h?
The correct answer is
42 km/h
Average speed = 2ab ÷ (a + b)
= 2 × 28 × 84 ÷ (28 + 84) = 4704 ÷ 112 = 42 km/h
Was this answer helpful?
Important Questions from Speed Time and Distance
- Daksh travels 200 km at 50 km/hr, the next 252 km at 42 km/hr and the next 204 km at 51 km/hr. What is his average speed (in km/hr) for the whole journey? (Round off your answer to two decimal places)
- A bus travelling at 66 km/hr completes a journey in 15 hours. What should be its speed to cover the same distance in 5 hours?
- Train A leaves station M at 8:00 a.m. and reaches station N at 3:00 p.m. on the same day. Train B leaves station N at 10:00 a.m. and reaches station M at 3:00 p.m. on the same day. Find the time when Trains A and B meet.
- A bus travelling at 95 km/hr completes a journey in 10 hours. What should be in its speed to cover the same distance in 5 hours?
Rishi travels 198 km at 66 km/hr, the next 584 km at 73 km/hr and the next 656 km at 82 km/hr. What is his average speed (in km/hr) for the whole journey? (Round off your answer to two decimal places)
Need Expert Advice?
