The following is a puzzle I found while reading Perfectly Reasonable Deviations from the Beaten Track by Richard P Feynman.
There are 2 shops which sell oranges.At Shop A you get 2 oranges for 5 cents.At Shop B you have to pay 3 cents for each orange.Richard bought some oranges from both the shops.He totally spent 19 cents.How many oranges did Richard buy?How many did he buy from each shop?
Note that Richard did NOT buy 7 oranges.I tried all the conventional methods I know and still ended up with 7 but it's specifically mentioned that the answer is not 7.
Thanks in advance.