A and B start walking towards each other at 1pm at speed of 5kmph and 7kmph. They were initially 24km apart. At what time do they meet?	Choose the correct answer:
A) 4 pm  B) 6 pm  C) 3 pm  D) 10 pm  E) 5 pm

Rationale: "time of meeting = distance / relative speed = 24 / 7 + 5 = 24 / 12 = 2 hrs after 1 pm = 3 pm answer is c"
Answer: C