A math problem … The number of this problem stumped hundreds of millions of people … How many people in China are illiterate …
The speed ratio of Party A and Party B is 4:5 and the time ratio is 5:4. It takes 12 hours for the B train to travel from point A to point B. When the B train travels to point B, it will return immediately and walk 150 kilometers. Car A arrived at point B just at the same time. If the speed difference is known, the speed of car B can be calculated as 150 ÷ (15-).