Debbie wants to swim across the river and emerge exactly across the river from where she enters the water. But she sees that there is a current, and she knows if she swims straight across and ignores the current she will land downstream. Debbie knows that she can swim at 4 miles per hour in still water, and that the current is running at 3 miles per hour. In order to land exactly across from her starting place, she needs to angle herself to swim on a trajectory which is slightly upstream. What is the angle, rounded to the nearest degree, that she needs to achieve to land where she wants to?