he spend: 1440 2.5=3600 he earn: 0.25 1440 12=4320 [because he sells 0.25/each and buy 1440 dozen so 1440 12]
4320-3600=720
The businessman buys 1,440 dozen pens for $3,600 and sells them for a total revenue of $4,320. Therefore, his total profit is $720. This profit is calculated by subtracting the total costs from the total revenue he earns from selling all the pens.
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