Two secretaries, Sally and Lisa, type at even but difference paces. Sally is more experienced and types 80 characters per minute. Lisa, a beginner, can type only 30 characters per minute. On one day, Lisa starts typing before Sally. At some point, both have typed the same number of characters. Then both continue typing and Sally types 800 more characters until her computer breaks down. Assuming Lisa does not take any break, how long, in hours, will it take her to finish typing the same number of characters?
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A$$\frac{53}{180}$$
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B$$\frac{4}{9}$$
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C$$\frac{13}{18}$$
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D$$\frac{15}{23}$$
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E$$\frac{5}{18}$$
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正确答案: E