Question 1116908
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(a) Explain why his profit for any day is £ (4x -20) , where X is the number of haircuts in a that day .
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Profit is Revenue minus Cost.



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He hopes to make at least £50 profit per day , but does not intend to make more than £120 profit.
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{{{50<=4x-20<=120}}}


{{{70<=4x<=140 }}}


{{{17.5<=x<=30}}}


In a simpler way, only allowing that no fraction of a haircut,
{{{18<=x<=30}}}.