8 1- 18=63

7 1- 17=54

92-29=63

82-28=54

93-39=54

2) Suppose that B just caught up with A at 1 hour, and A * * * ran for 2 hours+1 hour, with a distance of 15 km. At this time, b is15km/h.

Suppose B just catches up with A in 1.25 hours, and A * * * runs for 2 hours+1.25 hours, with a distance of 3.25*5= 16.25 kilometers. At this time, the speed of B is13km (16.25/ 1