Anu drives her car for 1 hour at a speed of 60km/h, for 2 hours at a speed of 55km/h, and for 3 hours at a speed of 45km/h. What is the average speed of the car (in km/h)?
- A50
6
5
- B52
2
1
- C48
3
1
- D49
Solution & Step-by-step Explanation
The formula for average speed is:
Average Speed=
Total Time
Total Distance
Step 1: Calculate total distance traveled
Distance in the 1st interval = 1hour×60km/h=60km
Distance in the 2nd interval = 2hours×55km/h=110km
Distance in the 3rd interval = 3hours×45km/h=135km
Total Distance=60+110+135=305km
Step 2: Calculate total time taken
Total Time=1+2+3=6hours
Step 3: Compute average speed
Average Speed=
6
305
=50
6
5
km/h
Average Speed=
Total Time
Total Distance
Step 1: Calculate total distance traveled
Distance in the 1st interval = 1hour×60km/h=60km
Distance in the 2nd interval = 2hours×55km/h=110km
Distance in the 3rd interval = 3hours×45km/h=135km
Total Distance=60+110+135=305km
Step 2: Calculate total time taken
Total Time=1+2+3=6hours
Step 3: Compute average speed
Average Speed=
6
305
=50
6
5
km/h