Analysis:

1, "The speed ratio of A and B is 2: 3". Then, the total time ratio between A and B is 3: 2. (The stroke is fixed, and the speed is inversely proportional to the time)

2. The complete travel time of Bank B is 5.5 ÷ 3× 2 = 1 1/3 hours.

3. The whole journey 1, a trip per hour1÷ 5.5 = 2/11; B hour line1÷11/3 = 3/11.

4.1÷ (2/11+3/1) = 2.2 hours.

the second question

Analysis:

1, the number ratio of cars to horses is 1: 3, and the number ratio of horses to people is 1: 7 = 3: 2 1. Then: car: horse: person = 1: 3: 2 1.

2. Every car crossing the river pays 30 yuan ferry fee, every carriage crossing the river pays 20 yuan ferry fee, and everyone crossing the river pays 2 yuan ferry fee. Then,1× 30+3× 20+21× 2 =132 yuan (each ferry fee).

3. 6600- 132 = 50 copies.

4、

1× 50 = 50 vehicles

3× 50 = 150 cars (carriage)

2 1× 50 = 1050 people