A and B start from a and return to B at the same time. They meet B at 45km away from B. the speed ratio of a and B is 3:2. How many kilometers does B walk when they meet?

A and B start from a and return to B at the same time. They meet B at 45km away from B. the speed ratio of a and B is 3:2. How many kilometers does B walk when they meet?

Tong 102030,
（45+45）÷（3-2）/2
=90÷1/2
=180 km
A: B walked 180 kilometers when they met

It's 120 km from a to B. car a and car B have been driving for 3 / 4 hours. When they meet, car a's speed is 4 / 5 of car B's. what's the average speed of car a and car B?

Suppose the speed of car B is x, then the speed of car a is (4 / 5) X. according to the meaning of the question, we get: [(4 / 5) x + x] * (4 / 3) = 120
The solution is x = 50km / h, (4 / 5) x = 40km / h
That is to say, the average speed of car a and car B is 40km / h and 50km / h respectively