That depends on weather you have a package or a letter, if its going by aeroplane or boat etc....your local royal mail post office will be able to help you out.
3 stamps!
700 Stamps
5
If this is just a post card you will only need the one stamp to mail it within the US.
There are various prices for stamps in Ireland. To send a letter in Ireland to other parts of Ireland, the price is 55 cent.
3
I suppose you need one or two stamps to send the president. But my guess is just one.
Regular postage works to an APO or SPO address. Non-military, I don't know.
1 I....think maybe 2
3 Forever Stamps should work just fine.
The number of stamps that you need to send a letter from Australia to London, will depend with the value of one stamp.
4 stamps