From 10:15 a.m. to 12:00 p.m. there are 1:45 hours. From 12:00 p.m. to 4:45 p.m. there are 4:45 hours therefore, each day Mr. Douglas works
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hours.
Now, each week, Mr. Douglas works 4 days therefore, in one week, he works:
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hours. Simplifying the above resut we get:

Finally, in four weeks Mr.Douglas works:

Answer:
