Yolanda is saving money to buy a game. so far she has saved
$20 , which is four-fifths of the total cost of the game. how much does the game cost?

Use mathematical induction to prove the statement is true for all positive integers n, or show why it is false. 1^2 + 4^2 + 7^2 + + (3n - 2)^2 = [n(6n^2-3n-1)/2]