Spelling mistakes in a text are either nonword errors or word errors. A nonword error produces a string of letters that is not a word, such as the typed as teh. Word errors produce the wrong word, such as loose typed as lose. Nonword errors make up 25% of all errors. A human proofreader will catch 80% of nonword errors and 50% of word errors. What percent of errors will the proofreader catch?

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