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?
Choose the correct choice from the following options
A) 3.2 hr
B) 3.4 hr
C) 3.6 hr
D) 3.8 hr
E) 4.2 hr

Rationale: let see d / t = v then x / 20 + ( 400 - x ) / 70 = 8 x = 64 kmh t = 64 / 20 = 3.2 hr answer : a
Answer: A