Two friends plan to walk along a 36-km trail, starting at opposite ends of the trail at the same time. If Friend P's rate is 25% faster than Friend Q's, how many kilometers will Friend P have walked when they pass each other? Choose the correct choice from the following answers.
A) 19 B) 20 C) 21 D) 22 E) 23

Rationale: if q complete x kilometers , then p completes 1.25 x kilometers . x + 1.25 x = 36 2.25 x = 36 x = 16 then p will have have walked 1.25 * 16 = 20 km . the answer is b .
Answer: B