The convenient number of sausages/buns

In Sweden, if you buy hot dogs and bread for hot dogs they come in packs of 10 or 30 hot dogs and packs of 12 buns. Since the numbers do not match, you have to eat 60 hot dogs before the number of buns and hot dogs are even.

In Japan, at least in the store I go to, there are 6 buns in a pack and 6 sausages in a pack. Very convenient. Then again, buying one 6-pack of buns and one 6-pack of sausages costs about the same as buying 60 sausages and 60 buns in Sweden...