If a person walks at 10 km/hr instead of 5 km/hr, he would have walked 20 km more. The actual distance traveled by him is?  Choose the correct choice from the following choices.
A) 50 km B) 76 km C) 20 km D) 16 km E) 97 km

Rationale: "let the actual distance traveled be x km . then , x / 5 = ( x + 20 ) / 10 5 x - 100 = > x = 20 km . answer : c"
Answer: C