Is 60inches=6ft if not please tell me

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?

What is always true when two whole numbers are subtracted?

Calculate the missing value. round the answer to on decimal place. start with 70, increase it by 21%, and end up with