Typing inverted question/exclamation marks

Keyboard layout: USA International (with dead keys)

¿ — Alt(R) + ?

¡ — Alt(R) + !

á — Alt(R) + a

Á — Alt(R) + Shift + a

é — Alt(R) + e

É — Alt(R) + Shift + e

í — Alt(R) + i

Í — Alt(R) + Shift + i

ñ — Alt(R) + n

Ñ — Alt(R) + Shift + n

ó — Alt(R) + o

Ó — Alt(R) + Shift + o

ú — Alt(R) + u

Ú — Alt(R) + Shift + u

ü — Alt(R) + y

Ü — Alt(R) + Shift + y

using Fourth Level Choosers

Press AltGr+Shift[held in]+ tap twice on 1 key to get ¡
Press AltGr+Shift[held in]+ tap twice on ? key to get ¿

or a bit harder why bother ::))

on Ubuntu press CTRL+SHIFT keep them in , press U and release U then following numbers and letters and release CTRL+SHIFT; then letter/symbol appears

IT IS ACTUALLY QUITE EASY !

¿ 00BF
¡ 00A1

and see here for more routes