Can a percent markup be 100% or 200%? what about a percent markdown?

Markup . . .

-- I buy a cabbage for $1.00 and put it on the shelf in my store. 
-- I mark it up 100% . . . I offer it for sale for $2.00
-- I mark it up 200% . . . I offer it for sale for $3.00 .

Markdown . . .

-- I buy a cabbage for $1.00 and put it on the shelf in my store. 
-- I mark it down 100% . . . I sell it for zero.  (I give it away.)
-- I mark it down 200% . . . I give you $1.00 to take it home with you.

-3/2

Step-by-step explanation:

There are three steps in calculating the slope of a straight line when you are not given its equation.

Step One: Identify two points on the line.

Step Two: Select one to be (x1, y1) and the other to be (x2, y2).

Step Three: Use the slope equation to calculate slope.

(x1,y1) → (2,10) and (x2,y2) → (4,7)7 - 10 = -34 - 2 = 2

Slope: -3/2

Hope I helped answer the question:)