Respuesta :

Answer;

Average speed  = 47.5 km/hr

Explanation and solution;

Average Speed = Total distance /Total time

Total distance;

-In the first two hours travelling at 40km/hr, total distance traveled is 80km.

(40 × 2) = 80 km

-In next two hours distance covered is 110 km. (55 ×2)

Total distance = 110 + 80 = 190 km

Total time = 2 + 2 = 4 hours

Average Speed = Total distance /Total time

                          = 190/4

                         = 47.5 km/hr