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A soccer player computes his win ratio by dividing the number of matches he has won by the total number of matches he has played. At the start of a weekend, his win ratio is exactly~$0.5$. During the weekend, he plays five games, winning three and losing two. At the end of the weekend, his win ratio is greater than~$0.505$. What\textquotesingle s the largest number of matches he could\textquotesingle ve won before the weekend began? 
Overseas Competition->Knowledge Point->Calculation Modules
Assume she won~$x$~games before the weekend, we obtain the inequality~$\frac{x+3}{2x+5}\gt0.505$~. Solve the inequality, we get~$x\lt47.5$ 