For a pile of goods, it takes 6 hours for car a to transport alone; for car B to transport alone, it takes 8 hours. Now, how many hours does it take for car a and car B to transport 7 / 8 of this pile of goods together? I'm in a hurry

For a pile of goods, it takes 6 hours for car a to transport alone; for car B to transport alone, it takes 8 hours. Now, how many hours does it take for car a and car B to transport 7 / 8 of this pile of goods together? I'm in a hurry

Car a transports 1 / 6 of the goods per hour
Car B transports one eighth of the goods per hour
The two teams can transport 1 / 6 + 1 / 8 of this pile of goods per hour = 7 / 24
To transport 7 / 8 of the goods, it takes 7 / 8 ／ 7 / 24 = 3 hours

For a batch of goods and materials, it takes 4 hours for car a to transport them separately and 6 hours for car B to transport them separately. Now, how many hours does it take for car a and car B to transport 56% of the goods and materials together?

56 △ 14 + 16, = 56 △ 512, = 2 hours; a: 2 hours