A pile of goods can be transported in 6 hours by car a alone, and in 8 hours by car B alone. Now how many hours can half of the goods be transported by car a and car B together?

A pile of goods can be transported in 6 hours by car a alone, and in 8 hours by car B alone. Now how many hours can half of the goods be transported by car a and car B together?

1 (16 + 18) × 12, = 1 △ 724 × 12, = 247 × 12, = 157 (hours). A: now, half of the goods can be transported in 157 hours by Party A and Party B

A batch of goods is transported by two vehicles of Party A and Party B, each vehicle carries six times. After the freight is completed, vehicle B carries 20% of the goods three times, and vehicle a carries 24 tons. How many tons of the goods are there?

Car B carries 20% of the goods in three times, that is 20% * 2 = 40% in six times, that is 1-40% = 60% in car a, and because car a carries 24 tons, so 24 / 60% = 40 tons

A. B vehicles transport construction materials to the construction site 6300 meters away from a certain place at the same time. A vehicle arrives 1 / 25 hours earlier. It is known that the speed ratio of a and B vehicles is 7:5
How many kilometers per hour does car a travel?

Suppose the speed of car a is x km / h, then the speed of car B is 5 / 7 x km / h. 6300 M = 6.3 km
6.3/x+1/25=6.3/（5/7x)
x=63km/h

It takes 20 days for Party A to transport a batch of building materials alone, and 15 days for Party B to transport them alone. After 8 days for Party A to transport alone, Party B will transport them alone, and it will take several days to complete

The completion ratio of the first day is 1 / 20
The completion ratio of the second day is 1 / 15
So 8 days is 8 / 20. The remaining 12 / 20
Then the remaining B need to transport days is 12 / 20 divided by 1 / 15, which is equal to 9 days