A car covers 1/3 distance with speed 20 km/hr and 2/3 with 60 km/hr. Average speed is1. A. 40 km/hr2. B. 50 km/hr3. C. 36 km/hr4. D. 80 km/hr
Question
A car covers 1/3 distance with speed 20 km/hr and 2/3 with 60 km/hr. Average speed is1. A. 40 km/hr2. B. 50 km/hr3. C. 36 km/hr4. D. 80 km/hr
Solution
The average speed of a journey is given by the total distance travelled divided by the total time taken. In this case, the total distance is split into two parts, 1/3 and 2/3, each covered at different speeds.
Step 1: Calculate the time taken for each part of the journey.
For the first 1/3 of the journey, at 20 km/hr, the time taken is (1/3) / 20 = 1/60 hours.
For the remaining 2/3 of the journey, at 60 km/hr, the time taken is (2/3) / 60 = 1/30 hours.
Step 2: Add these times together to get the total time taken.
Total time = 1/60 + 1/30 = 1/20 hours.
Step 3: The average speed is then the total distance (1) divided by the total time (1/20), which gives an average speed of 20 km/hr.
So, none of the options A, B, C, D is correct. The average speed is 20 km/hr.
Similar Questions
A vehicle moves for half of its time at 80 km/h and for rest half of time at 40 km/h. Total distance covered is 60 km. What is the average speed of the car.A 60 km/h B 80 km/h C 120 km/h D 180 km/h
A car travels a total distance of 400 km. It covers the first half of the distance at a speed 40 km/h and the second half of the distance at speed v. If the average speed is 48 km/h, then the value of v in km/h is 60 km/h87 km/h79 km/h94 km/h
A car travels 60 km/h for 1.5 hours. then it travels for 3 hours at 45km/h. After that, it covers 55km in 30 minutes. what is the average speed of the car for the entire journey
A car travels a distance of 80 km. For the first 30 minutes it is driven at a constant speed of 80 km/hr. The motor begins to vibrate and the driver reduces the speed to 40 km/hr for the rest of the trip. The average speed for the entire trip is Question 4Answera.47.5 km/hrb.50 km/hrc.60 km/hrd.40 km/hre.53.3 km/hr
A car travels at 54 km/hr for first 20 secs , 36 km/hr for next 30 secs and finally 18 km/hr for next 10 secs. Find its average speed.
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.