Question 1142493
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1)    https://www.britannica.com/science/are

      The are is a basic unit of area in the metric system, equals to 100 square meters.



2)    https://en.wikipedia.org/wiki/Hectare

     The hectare is an SI accepted metric system unit of area equal to a square with 100-meter sides, or 10,000 m2.



After providing this info, I am in position now to solve the problem.


 
To get the time to complete the job, take the total area 3.03 hectares, convert it to ares


    3.03 hectares = 303 ares


subtract the area of the warehouse  


    303 ares - {{{(60*50)/100}}} ares = 303 - 3 = 300 ares


and divide it by 42 {{{ares/day}}}.
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