Help with 6grade math​

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?

The weight of an object in the water is 7% of its weight out of the water. what is the weight of a 652g object in the water?

Plz ( true - false) all triangles have interior angles whose measure sum to 90.