Car a and car B travel from the same place in opposite directions. Car a travels 68 kilometers per hour and car B 72 kilometers per hour. Car a starts to leave one hour before car B starts to leave. After 2.5 hours, how many kilometers is the distance between car a and car B?

Car a and car B travel from the same place in opposite directions. Car a travels 68 kilometers per hour and car B 72 kilometers per hour. Car a starts to leave one hour before car B starts to leave. After 2.5 hours, how many kilometers is the distance between car a and car B?

(1 + 2.5) * 68 + 2.5 * 72 = 418km
A: the distance between the two vehicles is 418 km

A bus and a truck leave from station a and station B at the same time. When they meet in 4 hours, it takes 9 hours for the bus to complete the whole journey,
How many kilometers is the distance between station a and station B?

The speed of the bus is 60 * 4 / (9-4)
=60*4/5
48km/h
The distance between a and B is 48 * 9 = 432km
A: the distance between a and B is 432km

The distance between a and B is 392 kilometers. The bus starts from a place 70 kilometers per hour, and the car starts from B place 85 kilometers per hour after 20 kilometers. The two cars meet on the way

(392-20) / (70 + 85) = 372 / 155 = 2.4 (hours)

Divide a batch of parts equally to Party A and Party B for processing at the same time. They work for 5 days and complete 23% of this batch of parts. It is known that the efficiency ratio of Party A and Party B is 5:3. How many days will it take for Party B to complete the assigned task?

Let B's work efficiency be x, then a's work efficiency is 53x, then: 5x + 5 × 53x = 23 & nbsp; 5x + 253x = 23 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; X = 120 (12-23 × 33 + 5) △ 120 = 14 △ 120 = 5 (days) a: it will take 5 days for B to complete the assigned task