<PRE><B>Question 205480</B>
D is the total distance and the time (t) is in hours so,


First section: D/(10*6) = t1


Second section: D/(6*12) = t2


Third section: D/(5*24) = t3


Last section: 32/48 = t4


He has travelled D/10 + D/6 + D/5 (=7D/15) of the way so has 8D/15 left which is 32 km. Therefore D = 60 km.

t1 = 60/60 = 1 hour

t2 = 60/72 = 50 minutes

t3 = 60/120 = 30 minutes

t4 = 32/48 = 40 minutes

Total time T = t1 + t2 + t3 + t4 = 3 hours.


Checking:

6 km at 6 km/h is an hour (6 km is 1/10)

10 km at 12 km/h is 50 minutes (10 km is 1/6)

12 km at 24 km/h is 30 minutes (12 km is 1/5)

32 km at 48 km/h is 40 minutes (32 km is 8/15)


Total distance is 60 km and total time is 3 hours.</PRE>