a car covers 1/3 part of the total distance with a speed 20 km /h and the remaining distance with speed 44 km / h. Find the average speed of the car?
Answers
Let the total distance be x km.
A car covers 1/3 part of total distance with speed of 20 km/hr & remaining distance with a speed of 44 km/hr.
We know time = distance/speed
1st part journey time:
Distance = x/3 km
Speed = 20 km/hr
Time = x/3 km / 20 km/hr
Time = x/60 hours
2nd part journey time:
Distance = x - x/3 = 2x/3 km
Speed = 44 km/hr
Time = 2x/3 km / 44 km/hr
Time = 2x/132 hours
The average speed is total distance divided by total time. Accordingly
Total distance = x km
Total time = x/60 + 2x/132
Average speed = x / x/60 + 2x/132
= x / (11x + 10x)/660
= x × 660/21x
= 660x / 21x
= 660/21
= 31 3/7 km/hr
Or 31.4286 km/hr
Average speed = 31 3/7 km/hr or 31.4286 km/hr for entire journey
Answer : the average speed of the car is 31 3/7 km/hr or 31.4286 km/hr for entire journey
Answer:
Explanation:
Let the total distance be x km.
A car covers 1/3 part of total distance with speed of 20 km/hr & remaining distance with a speed of 44 km/hr.
We know time = distance/speed
1st part journey time:
Distance = x/3 km
Speed = 20 km/hr
Time = x/3 km / 20 km/hr
Time = x/60 hours
2nd part journey time:
Distance = x - x/3 = 2x/3 km
Speed = 44 km/hr
Time = 2x/3 km / 44 km/hr
Time = 2x/132 hours
The average speed is total distance divided by total time. Accordingly
Total distance = x km
Total time = x/60 + 2x/132
Average speed = x / x/60 + 2x/132
= x / (11x + 10x)/660
= x × 660/21x
= 660x / 21x
= 660/21
= 31 3/7 km/hr
Or 31.4286 km/hr
Average speed = 31 3/7 km/hr or 31.4286 km/hr for entire journey
Answer : the average speed of the car is 31 3/7 km/hr or 31.4286 km/hr for entire journey