A ship can use up to 6 hours of diesel oil. When it goes out, it goes with the wind, 30 kilometers per hour. When it goes back, it goes against the wind, and the distance per hour is 45 times of that when it goes with the wind?

A ship can use up to 6 hours of diesel oil. When it goes out, it goes with the wind, 30 kilometers per hour. When it goes back, it goes against the wind, and the distance per hour is 45 times of that when it goes with the wind?

If it takes x hours to go out and 6-x hours to come back, the equation is: 30x = 30 × 45 × (6-x), 30x = 24 × (6-x), 30x = 144-24x, 54x = 144, & nbsp; X = 83.30 × 83 = 80 (km). A: this ship should go back at most 80 km

Car a and car B leave from city a and city B at the same time, meet each other seven hours later, and then drive forward for two hours. At this time, car a is 240 kilometers away from city B, and car B is 360 kilometers away from city A. how many kilometers are there between city a and city B?

(240 + 360) △ 7-2) × 7 = 600 △ 5 × 7 = 120 × 7 = 840 (km). A: the distance between a and B is 840 km

Four football teams play a single round robin game, and every two teams have to play one game. If they are tied, each team will get one point, otherwise the winning team will get three points, and the negative team will get zero points. As a result, there are four draws, and the total score of each team is just four consecutive natural numbers. What is the total score of the team who lost to the first place?

4 × (4-1) △ 2 = 6 games, that is to say, there are 6 games in total, and the total score of each team is just four consecutive natural numbers. Then the first place must not win two games, otherwise the score is not continuous. There are two teams that win only one game, and the other two teams don't win one game, because they win at least three points in one game and don't win at most three points in one game