Из одного города одновременно в противоположных направлениях выехали 2 автобуса.Скорость первого 36 км\час,второго-45 км\час.Какое расстояние будет между ними через 3 часа?

Расставить предлоги 

we are students... the morning we go .... the institute. our lectures begin ... 9 o'clock. we have no lectures ... sunday. we take examinations ... january and June. we do not study ... summer. we come... the classroom and sit down... the table. we take our books and notebooks... the bags and put them...the table. our pens are...the table too. our bags are usually...the tables. sometimes they are...the table...the floor. during the lesson we go...the blackboard and write sentences... it. when the lessons are over we go... the classroom and go home. we usually come back...the institute...3 o'clock...the afternoon.