Please help me with this question i need it quick!

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?

Ageologist had two rocks on a scale that weighed 4.6 kilograms together. rock a was 0.5 of the total weight. how much did rock a weigh?

Asap (i need to finish this quick) graph complete the sequence of transformations that produces △x'y'z' from △xyz. a clockwise rotation ° about the origin followed by a translation units to the right and 6 units down produces δx'y'z' from δxyz.