Tharak covers a part of the journey at 20 kmph and the balance at 70 kmph taking total of 8 hours to cover the distance of 400 km. How many hours has been driving at 20 kmph?  Choose the correct choice:
A) 3 hours 12 minute
B) 2 hours
C) 4 hours 40 minutes
D) 3 hours 20 minutes
E) 3 hours 18 minute
Let x be no. Of hours, and he travelled at 20kmph.   And balance distance (8-x)hr at 70kmph.   Total distance=20x+(8-x)hr =400   20x+(8-x)70=400   20x+560-70x=400   20x-70x=400-560   -50x=-160   x=3.2 =3 hr 12minutes   3 hours 12 minuteNSWER:3 hours 12 minute
<result>A</result>
Tharak covers a part of the journey at 20 kmph and the balance at 70 kmph taking total of 8 hours to cover the distance of 400 km. How many hours has been driving at 20 kmph?