50% of the apartment in a certain building have windows and hardwood floors. 25% of the apartments without windows have hardwood floors . If 40% of the apartments do not have hardwood floors , what percent of the apartments with windows have hardwood floors???
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Assume there are x apartments in a certain building and w have windows.
0.50(x) = Number of apartments with windows and hardwood floors
0.25(x-w) = Number of apartments without windows that have hardwood floors.
0.75(x-w) = Number of apartments with no windows or hardwood floors.
w - 0.5(x) = Number of apartments with only windows
w - 0.5(x) + 0.75(x - w) = 0.4(x)
0.25w + 0.25(x) = 0.4(x)
w = 0.15(x)/0.25 = 3x/5
0.50(x)/(0.6(x)) = 5/6 or 83.33%
0.50(x) = Number of apartments with windows and hardwood floors
0.25(x-w) = Number of apartments without windows that have hardwood floors.
0.75(x-w) = Number of apartments with no windows or hardwood floors.
w - 0.5(x) = Number of apartments with only windows
w - 0.5(x) + 0.75(x - w) = 0.4(x)
0.25w + 0.25(x) = 0.4(x)
w = 0.15(x)/0.25 = 3x/5
0.50(x)/(0.6(x)) = 5/6 or 83.33%