Question 1153433
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<pre>
Their profit is 120-40 = 80 dollars for each adult bicycle and 90-30 = 60 dollars for each child bicycle.


The total profit is thus


    P = 80x + 60y.


The inequality the problem asks to write is


    80x + 60y >= 2400.
</pre>

Solved, answered and explained.  And completed.