Which unit (mm, cm, m, or km) would be the most appropriate for each measurement? a distance across lake michigan b length of a spoon c thickness of an envelope d height of a building

Atourist boat is used for sightseeing in a nearby river. the boat travels 2.4 miles downstream and in the same amount of time, it travels 1.8 miles upstream. if the boat travels at an average speed of 21 miles per hour in the still water, find the current of the river.

There are a total sales of 2,000 dollars on monday on tuesday sales dropped 10% on wednesday sales dropped another 20% compared with tuesday from wednesday to thursday sales increases by an equal amount to 25% of monday total sales what is the net change in dollars on total sales from monday to tuesday

(25 ! ) what does it mean for an equation to have no solution or infinitely many solutions?