If a person walks at 20 km/hr instead of 10 km/hr, he would have walked 40 km more. The actual distance traveled by him is?	Choose the most appropriate option:
A) 40 km
B) 76 km
C) 18 km
D) 16 km
E) 97 km

Rationale: "let the actual distance traveled be x km . then , x / 10 = ( x + 40 ) / 20 10 x - 400 = > x = 40 km . answer : a"
Answer: A