By travelling at 80 kmph, a person reaches his destination on time. He covered two-third the total distance in one-third of the total time. What speed should he maintain for the remaining distance to reach his destination on time?  Choose the correct choice from the following choices:
A) 25 kmph  B) 40 kmph  C) 35 kmph  D) 46 kmph  E) 50 kmph

Rationale: "let the time taken to reach the destination be 3 x hours . total distance = 80 * 3 x = 240 x km he covered 2 / 3 * 240 x = 160 x km in 1 / 3 * 3 x = x hours so , the remaining 80 x km , he has to cover in 2 x hours . required speed = 80 x / 2 x = 40 kmph . answer : b"
Answer: B