Hi Trushit,
If the original price of an item is $100 and you increment it by 20%, the final price is $100 + 20/100 * 100 = 100+20 =
120If you discount the final price of $ 120 by 20%, we assume it to be $100 but it is not so.
The reason is: $120 - 20/100 * 120 = 120 -
24 =
$94 You notice...
20% of 120 is 24 not 20 so you are deducting more than what you actually added hence when you discount by the same value (20%), you wont get the same number.
In question you have posted, the author says - "A dress is marked up by 16 2/3% to make the final price of $ 140"
"marked up" means hiked the price... what you tried to do was "discount" the price by same % on the final price.. which is incorrect.
Hence, the problem has to be solved as follows:
let x be original price
% increase is = 16 2/3% of x = 50/3% of x
final price = $ 140
==> x + 50/3 * x% = 140
==> x + 50/300 * x = 140
==> x + x/6 = 140
==> 7x/6 = 140
==> x = 120
Hope I resolved your concern
_________________
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