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Question 406656: The original price of the book was decreased by 20% two times in one year. It now cost $180 less than the original price. What was the original price?
Answer by J2R2R(94)   (Show Source):
You can put this solution on YOUR website! Assuming it was reduced by 20% to 80% of its original price; and then this price was reduced by 20% to 80% of this price (not a further 20% of the original price bringing it to 60% of the original price), we would have 80% of 80% = 64%
So, if it now costs $180 less than the original price, the reduction is 1 - 64% = 36%
Therefore 36% of the total price is $180.
Since 36% is 9/25, the original cost is $180 times 25/9 = $500.
Let us check:
Original price $500
20% reduction is $100 bringing it to $400
A further 20% reduction is £80 bringing it to $320
The difference in the price id $500 - $320 = $180
Correct!
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