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.
Option 1: 20 km/hr
Option 2: 30 km/hr
Option 3: 25 km/hr
Option 4: 35 km/hr
Correct Answer: 25 km/hr
Solution : Let the total distance be 100 km. 1st 25% of distance = 25 km Speed = 25 km/hr Time = $\frac{\text{distance}}{\text{speed}}= \frac{25}{25}= 1$ hour 2nd 50% of distance = 50 km Speed = 50 km/hr Time = $\frac{\text{distance}}{\text{speed}}=\frac{50}{50}= 1$ hour Remaining distance = 100 – 25 – 50 = 25 km Speed = 12.5 km/hr Time = $\frac{\text{distance}}{\text{speed}}=\frac{25}{12.5}= 2$ hours Total time = 1 + 1 + 2 = 4 hours Average speed = $\frac{\text{Total distance}}{{\text{Total time}}}=\frac{100}{4}=25$ km/hr Hence, the correct answer is 25 km/hr.
Application | Eligibility | Selection Process | Result | Cutoff | Admit Card | Preparation Tips
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:
Option 1: 42 km/hr
Option 2: 40 km/hr
Option 3: 35 km/hr
Option 4: 45 km/hr
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
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:
Option 2: 50 km/hr
Option 3: 54 km/hr
Option 4: 55 km/hr
Question : A man goes from place A to B at a speed of 12 km/hr and returns from B to A at a speed of 18 km/hr. His average speed for the entire journey is:
Option 1: $14 \frac{2}{5} \mathrm{~km} / \mathrm{hr}$
Option 2: 15 km/hr
Option 3: 6 km/hr
Option 4: 30 km/hr
Question : In a journey of three unequal laps, a car covers a distance of 200 km in 4 hr in the first lap, while another 162 km at the speed of 15 m/s in the second lap. It covered the remaining distance of the final lap in 4 hr such that the average speed of the car for the entire journey was 50 km/hr. What was the speed of the car on the third lap of the journey?
Option 1: 47 km/hr
Option 2: 52 km/hr
Option 3: 42 km/hr
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile