A works for 5 days and B works for 3 days, which can be understood as two people working together for 3 days (3 divided by 15 equals 6/30), then A works for 2 days, and a * * * completes 7/30, that is to say, A takes 2 days to complete130, and it takes 60 days to divide by 2, so the total can be obtained according to the daily speed.
The answer is as follows: 2 ÷ (7/30-3 ÷15) x18 =1080.
Analysis 2: Suppose Xiao Wei's speed is 1, Xiaoming is 2, Xiaoming is four-fifths slower than the car, that is, only one-fifth of the car's speed, then the car's speed is 10, and two people are in opposite directions at first, then the distance is the sum of the speed of the car and Xiao Wei multiplied by the time, which is (1+10. Then Xiao Ming goes after them, that is, the distance between them is divided by the speed difference between them, that is, the meeting time is110 ÷ (2-1) =10.
The answer is as follows: (1+10) x10 ÷ (2-1) =10 seconds.