math
posted by peaches .
A necklace, priced between $50 and $100, was on sale at 25% off. When the original price (a whole dollar amount) was discounted, the sale price was also a whole number of dollars. What are the possible original prices for the necklace?

p is a whole number between 50 and 100
(3/4) p whole number
well p = 100 works (then get it for 75)
p = 80 works (then get it for 60)
as a matter of fact anything in there divisible by 4 works
52
56
60
64 etc 
I am trying to help my son with the same problem. At first I thought the above answer was correct too. Then I started to second guess myself because $50$100 is the SALE price so we need to find the ORIGINAL price THEN take 25% off that to get the sale price. The above answer (52, 56, 60, 64....) is if we take 25% off of the sale price ($50$100). I think we are doing it backwards. ????? I understand that it's every 4 numbers but I think it may be 68, 72, 76.....
If we assume $68 is the original price and take 25% of $68, then we get a sale price of $51. Any thoughts? Again, I have no idea which way is correct. 
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