A car covers four successive 8 km distances
A car covers four successive 8 km distances at speeds of 12 km/hr, 18 km/hr, 24 km/hr and 36 km/hr, respectively. Its average speed (in km/hr) over this distance is:
एक कार 8 km की चार क्रमिक दूरियाँ क्रमशः 12 km/hr, 18 km/hr, 24 km/hr और 36 km/hr की चाल से तय करती हैं। पूरी दूरी के लिए इसकी औसत चाल (km/hr में) कितनी हैं?
Detailed Solution & Logic
Correct Answer:
19.2
Each distance = 8 km
Total distance = 32 km
Total time = $ \dfrac{8}{12} + \dfrac{8}{18} + \dfrac{8}{24} + \dfrac{8}{36} $
= $ \dfrac{2}{3} + \dfrac{4}{9} + \dfrac{1}{3} + \dfrac{2}{9} $
= $ \dfrac{15}{9} = \dfrac{5}{3} $ h
Average speed = $ \dfrac{32}{5/3} $= 19.2 km/h
Answer: 19.2 km/h
Similar Practice Questions
Two trains, 232 m and 248 m in length, are running in opposite directions.
Two trains, 232 m and 248 m in length, are running in opposite directions. The...
A motorboat travelling at some speed can cover 24 km upstream and 40 km downstream in 17 hours.
A motorboat travelling at some speed can cover 24 km upstream and 40 km downstream...
Amir goes to his college from his house at a speed of 4km/hr and returns at a speed of 2 km/hr.
Amir goes to his college from his house at a speed of 4km/hr and returns...
Ravi goes to college from his village
Ravi goes to college from his village at the speed of 5km/h and returns at...
A bike travels 94 meters in one second. Find its speed (in km/h).
A bike travels 94 meters in one second. Find its speed (in km/h). एक बाइक...
In a circular race of 1500 m, P and Q start
In a circular race of 1500 m, P and Q start from the same point...
The average speed of a car running at 70 km/hr for 1 hour and ‘P’ km/hr for $1\frac{1}{2}$ hour is 55km/hr. Find the value of p
The average speed of a car running at 70 km/hr for 1 hour and ‘P’...