A car covers one third part of the total distance with the speed of 20 km per hour and the remaining distance with the speed of 44 kilometre per hour. Find the average speed of the car.
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Answers
Answer:
31.4286 is the average speed. ~ 31.42
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