Prove that there exists a positive integer $n$ such that the equation $x^2 + y^2 = n$ has at least 2005 solutions in non-negative integers $x$ and $y$.

34 cup. a serving of vegetable soup is 23 cup. the restaurant sold 20 servings of chicken noodle soup and 18 servings of vegetable soup. how many more cups of chicken noodle soup did they sell than cups of vegetable soup?

Thales was an ancient philosopher familiar with similar triangles. one story about him says that he found the height of a pyramid by measuring its shadow and his own shadow at the same time. if the person is 5-ft tall, what is the height of the pyramid in the drawing?

Fa bus driver leaves her first stop by 7: 00 a. m., her route will take less than 37 minutes. if she leaves after 7: 00 a. m., she estimates that the same route will take no less than 42 minutes. which inequality represents the time it takes to drive the route, r?