Question : During a journey of 120 km, Rahi drives the first 60 km at the speed of 60 km/hr, the next 30 km at 60 km/hr and the remaining 30 km at the speed of 30 km/hr. Determine the average speed.
Option 1: 48 km/hr
Option 2: 33.33 km/hr
Option 3: 50 km/hr
Option 4: 40 km/hr
Correct Answer: 48 km/hr
Solution : Rahi drives the first 60 km at the speed of 60 km/hr. Time taken $=\frac{60}{60}=1$ hour The next 30 km at 60 km/hr. Time taken $=\frac{30}{60}=\frac{1}{2}=0.5$ hour The remaining 30 km at the speed of 30 km/hr. Time taken $=\frac{30}{30}=1$ hour Total time taken = 1 + 0.5 + 1 = 2.5 hours Total distance = 120 km $\therefore\text{Average speed}=\frac{\text{Total distance}}{{\text{Total time}}}=\frac{120}{2.5}=48$ km/hr Hence, the correct answer is 48 km/hr.
Result | Eligibility | Application | Selection Process | Cutoff | Admit Card | Preparation Tips
Question : A truck goes from Haryana to Bangalore with an average speed of 60 km/hr. The journey takes 30 hours. It returns from Bangalore to Haryana on the same road with an average speed of 40 km/hr. What was the average speed of the truck during the roundtrip?
Question : A man covers a certain distance by bike. If he covers 25% of the distance at the speed of 25 km/hr, 50% of the distance at the speed of 50 km/hr and the remaining distance at the speed of 12.5 km/hr, find his average speed over the whole journey.
Question : On a journey across Kolkata, a taxi averages 50 km/hr for 50% of the distance, 40 km/hr for 40% of it and 20 km/hr for the remaining. The average speed (in km/hr) for the whole journey is:
Question : A man goes from Mysore to Bangalore at a uniform speed of 40 km/hr and comes back to Mysore at a uniform speed of 60 km/hr. His average speed for the whole journey is:
Question : A boy goes from home to school at a speed of 30 km/hr and returns back at a speed of 70 km/hr. What is his average speed for the journey?
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile