No simple answer. This is a complex question, as something has no tax, something has only one tax, something have both, something to a certain number of items have no tax, and on, and on.
for my experience
if you buy from the supermarket, all the unprocessed food, no tax,like the meat or fruits, milk
buy other stuff, most will be 15%
if you buy fastfood under 4 dollars, 7%, more than 4$, 15%
