2014 Fermat Problem 14

Last summer, Pat worked at a summer camp. For each day that he worked, he earned \$100 and he was not charged for food. For each day that he did not work, he was not paid and he was charged \$20 for food. After 70 days, the money that he earned minus his food costs equalled \$5440. On how many of these 70 days did Pat work?

\textbf{(A)}\ 60\quad \textbf{(B)}\ 68\quad \textbf{(C)}\ 50\quad \textbf{(D)}\ 57\quad \textbf{(E)}\ 34

If there are no answer choices shown, enter a numerical answer.

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