so, she had 75 fliers total, then she posted 2/5, how much is 2/5 of 75? well, is just their product,
[tex]\bf 75\cdot \cfrac{2}{5}\implies \cfrac{150}{5}\implies 30
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\textit{how much is }\frac{2}{3}\textit{ of }\stackrel{remaining~75-30}{45}\textit{ fliers?}\qquad 45\cdot \cfrac{2}{3}\implies \cfrac{90}{3}\implies 30[/tex]
so, she had 75 total, she posted 30, then 30 again, so she hasn't posted 75 - 30 - 30.