<PRE><B>Question 861765</B>
A Motorist travels 90 kms. with the speed of 60 km/hr and the next 40 kms distance with the speed of 40 km/hr.
 what is his average speed during the journey? 
:
let a = his average speed for the journey
:
The total distance is 90 + 40 = 130 km
Write a time equation; Time = dist/speed
{{{90/60}}} + {{{40/40}}} = {{{130/a}}}
1.5 + 1 = {{{130/a}}}
2.5a = 130
a = 52 km/hr is the av speed so are right|</PRE>