of a journey of 216km, 56km were on untarred road. for this part of the journey, a motorist could only average 28km/h. if his average speed for the whole journey was 48km/h, what was his average speed for the part of the journey on tarred road?

Respuesta :

Answer:

64 km/hr

Step-by-step explanation:

216 - 56 = 160 km on good road

216km / 48 km/hr = 4.5 hours total time

56 km / 28 km/hr = 2 hours on bad road

   then 2.5 hours on good road   ( for total 4.5 hrs)  

         160 km / 2.5 hr = 64 km/hr on the good road portion