- Ram 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?
(1) 2 hours (2) 3 hours 20 minutes (3) 4 hours 40 minutes (4) 3 hours 12 minutes
Solution:
Let x be the number of hours he travels at 20 kmph.
Distance covered in this x hours = 20x km
He would have therefore, traveled the balance (8 � x) hours at 70 kmph.
Distance covered in this 8 � x hours = (8-x) * 70 = (560 � 70x) km
The total distance traveled = 20x + 560 � 70x = 400
=>160 = 50 x
=>x = (160/50) hours = 3.2 hours = 3 hours and 12 minutes
