Please help me. you will get marked as brainlist. make sure to provide an explanation

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 jurassic zoo charges $14 for each adult admission and $5 for each child. the total bill for 77 people from a school trip was $565. how many adults and how many children went to the zoo? i

What is the name used to describe a graph where for some value of x, there exists 2 or more different values of y?