Let the aeroplane covers x km at a speed of 440 km/h and (x – 770) km at a speed of 660 km/h. Hence, it covers a total distance of (2x – 770) km at a speed of 500 km/h.
Average speed =
Totaldistance
Totaltime
⇒ 500 =
2x−770
x
440
+
x−770
660
or
2x−770
500
=
x
440
+
x−770
660
or x = 1760 Therefore, the total distance covered = 2x – 770 = 2 × 1760 – 770 = 2750 km