A and B start from ab at the same time and run in opposite directions. They meet at 80km away from the midpoint. The speed ratio of a and B is 4:5, and the distance between AB and B is calculated?

A and B start from ab at the same time and run in opposite directions. They meet at 80km away from the midpoint. The speed ratio of a and B is 4:5, and the distance between AB and B is calculated?

A and B start from ab at the same time and run in opposite directions. They meet at 80km away from the midpoint. The speed ratio of a and B is 4:5, and the distance between AB and B is calculated?
80÷【1/2-4/(4+5)】
=80÷【1/2-4/9】
=80÷1/18
=1440 km