Question 730075
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last month a store manager decided to decrease the prices of all items by 10%. this month he increased the prices by 10%. 
What would be the price for a pair of pants that had cost $750 before prices were decreased last month??
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<pre>
Last month the price decreased from 750 dollars to 750 - 0.1*750 = 750*(1-0.1) = 750*0.9 = 675 dollars.


This month the price increased from 675 dollars to 675 + 0.1*675 = 675*(1+0.1) = 675*1.1 = 742.50 dollars.


    
                           Notice here 
    that the price did not return to 750 dollars, the original level !



You can compose these long calculations into one short composition for two steps

      750 dollars  ----->  750*0.9*1.1 = 750*0.99 = 742.50 dollars


which gives you the same answer.


Notice this factor 0.99, which prevents the price to return to the original level ! !
</pre>

Solved, with explanations.



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Ignore the post by @lynnlo, since it gives wrong answer and is irrelevant.