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 Thread: Mathcounts Marathon View Single Post
 06-22-2007 #9 Sillysidley   Join Date: Oct 2006 Posts: 822 Yes, it's just supposed to be $b^2-4ac$ not $\sqrt{b^2-4ac}$ For your question, it's $25\pi$ Let someone else answer this, it's easy: What's the probability of drawing a yellow coin out of a bag with 4 yellow coins and 5 blue coins? __________________ .