Speed ratio = inverse ratio of time ratio

Then the time ratio of the complete trip between Bank A and Bank B = 1: 7/9.

B it takes 14 hours to complete the journey, so a needs 14/(7/9)= 18 hours.

When we met, the distance ratio between Party A and Party B was 7/9: 1 = 7: 9.

That is to say, Party A implements 7/ 16 and Party B implements 9/ 16.

A to the midpoint, line1/2-7/16 =116.

Then b (116)/(7/9) = 9/112 will do.

Then the distance between the two places =120/(9/16-1/2+9/12) = 840km.

Speed b = 840/14 = 60 km/h.

The speed of a = 60× 7/9 =140/3 km/h.

Going back from the middle point, B arrives at Line A 1/2, and then Line A 1/2×7/9=7/ 18.

At this time, the distance between A and B is still 840× (1/2-7/18) = 280/3 km.

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