An elevator goes from the 124 floor to the 8th floor of a skyscraper in 40 seconds. The elevator travels at a constant speed. What is the elevator's rate of change in floors per second?

A cable on a fishing boat lowers a fish trap into a lake at a rate of 3 $$\frac{1}{2}$$ feet per second. What is the change in the depth of the fish trap after 12 seconds?

Tyesha needs 17 $$\frac{3}{4}$$ feet of wood for a project. She has lengths of wood that are 7 $$\frac{1}{2}$$ , 5.25, and 6 $$\frac{3}{4}$$ feet long. Does Tyesha have enough wood for her project?