Question 1181757
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The break event is when  Total Cost = Revenue,  or


    39000 + 1200x = 1500x.


It gives


    x = {{{39000/(1500-1200)}}} = {{{39000/300}}} = {{{390/3}}} = 130 mowers.


<U>ANSWER</U>.  Break event is  130 mowers.
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Solved, answered and explained.