Analysis:
After Party A puts down Party C, the distance to Party B is 72-x-(72-x)/5, and the meeting time between Party A and Party B should be [72-x-(72-x)/5]/(25+5), so the distance to the library should be 72-(72-x)/5-5 × [72].
According to the meaning of the question,
x/5 =[72-x-(72-x)/5]/(25+5)+{ 72-(72-x)/5-5×[72-x-(72-x)/5]/(25+5)}/25
I'll go, this question. . . Ask the landlord for extra points
Solve x= 18.
The total time is (72-18)/25+18/5 = 5.76 hours.
Answer: C is 0/8km away from the library/kloc-when getting off the bus, and it takes 5.76 hours for three people.