Carin' For Seven Posted November 6, 2009 Share Posted November 6, 2009 Could someone please help me explain how to solve this problem to my kids. Thanks. Sandy typed a six-digit integer, but the two 9s she typed didn't show. If 2010 appeared, how many different positive six-digit integers could she have typed? One such integer to include is 920910. Answer: 15 Quote Link to comment Share on other sites More sharing options...
Julie in MN Posted November 6, 2009 Share Posted November 6, 2009 Could someone please help me explain how to solve this problem to my kids. Thanks. Sandy typed a six-digit integer' date=' but the two 9s she typed didn't show. If 2010 appeared, how many different positive six-digit integers could she have typed? One such integer to include is 920910. Answer: 15[/quote'] Don't you just have to create 6 blanks: __ __ __ __ __ __ And see how many ways you can plug TWO 9's into those blanks? 9 9 __ __ __ __ 9 __ 9 __ __ __ And so on.....? Julie Quote Link to comment Share on other sites More sharing options...
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