question_answer

An aero plane flies round a square field PQRS of each side 100 km. Its speed along PQ is 400 km/h, along QR is 500 km/h, along RS is 600 km/h and along SP is 700 km/h. The average speed of the aero plane over the entire trip is

Answer:

  \[Average\,speed=\frac{total\,\,dis\tan ce}{total\,\,time}\] \[=\frac{4\times 100}{\frac{100}{400}+\frac{100}{500}+\frac{100}{600}+\frac{100}{700}}\] \[=526.32\,\,km/h\]