Which are vertical angles?

Samantha swam upstream for some distance in one hour. she then swam downstream the same river for the same distance in only 12 minutes. if the river flows at 4 mph, how fast can samantha swim in still water?

How to determine whether two known pairs of points are on the same line.

Tom had a total of $220 and he spent $35 on a basketball ticket . what percent of his money did he have left?