A and B vehicles run from ab at the same time and meet 80 km away from the midpoint. If the speed ratio of a and B vehicles is 15:12, how many km is ab?

The speed ratio is the distance ratio when meeting, so when meeting, the distance a takes is 15 / (15 + 12) = 15 / 27
15/27-1/2=1/18
80/(1/18)=1440

Car a and car B start from two places at the same time and travel in opposite directions. Car a travels 75 kilometers per hour, and car B travels 80 kilometers per hour. When they meet, what is the simplest integer ratio of the distance traveled by car a and car B

15 to 16

At 8:00 a.m., a and B depart from ab at the same time and run opposite to each other. At 10:00 a.m., the distance between the two vehicles is 112.5 km. When the two vehicles continue to drive until 1:00 p.m., the distance between the two vehicles is 112.5 km. What is the distance between AB and ab?

8:00 to 10:00 in the morning is two hours (112.5 + 112.5) △ 3 × 2 + 112.5 = 75 × 2 + 112.5 = 150 + 112.5 = 262.5 (km) a: the distance between AB and ab is 262.5 km

Car a and car B travel from two places 340 kilometers apart. Car a starts at 8:40 a.m. and travels 30 kilometers per hour. Car B travels 35 kilometers per hour until 2:10 p.m
When did bus B start?

5 hours from 8:40 a.m. to 2:10 p.m;
When they met, car a traveled 30 × 5.5 = 165 km, and car B 340-165 = 175 km,
Then, when we met, car B traveled 175 △ 35 = 5 hours,
Therefore, the departure time of car B is 9:10 a.m

A and B vehicles run from ab at the same time and meet 80 km away from the midpoint. If the speed ratio of a and B vehicles is 15:12, how many km is ab?