The general function P(t) = P0ert is used to model a dying fish population, where n0 is the initial population and t is time measured in years. Suppose the population initially contains 700 fish and after 6 years there are only 28 fish remaining. How long did it take for the fish population to decline to one-fifth its initial size? Simplify your answer completely.

99 points at a zoo, the leopard pen has a ring-shaped sidewalk around it. the outer edge of the sidewalk is a circle with a radius of 12 m. the inner edge of the sidewalk is a circle with a radius of 8 m. (1 point for showing all of your work) a. write and simplify an expression for the exact area of the sidewalk. (1 point for the answer) b. find the approximate area of the sidewalk. use 3.14 to approximate π. (1 point for the answer)

The length of a rectangular piece of land is 92 yards more than three times its width. the perimeter is 760 yards. find its dimensions.

I’m confused on how to work the pie charts