You run 3 1/4 miles as a part of an exercise routine. You run 2/5 of that distance on a hill. You run down a slope for the last 1/2 of the hill. On how many miles of your run do you run down the slope? Write your answer as a fraction or mixed number in simplest form.

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?