Susan had 30 items of clothing in her wardrobe. She donated 20% of her clothing during a charity clothing drive at the school. How many items of clothing did Susan donate?

Afarmer has a large field that is x feet in length. he wants to fence in a rectangular section in the middle of the field , leaving a length of 100 feet of open field behind each end of the fenced rectangle.he also wants the width of the fenced-in space to be 100 feet less than its length. find the expressions to represent the length and width of the fenced section of the field