Typing inverted question/exclamation marks

I type a lot in Spanish and have a regular 105-key International Keyboard. So I have NO buttons for ñ or other accented letters. However, by setting the keyboard to "US Alternative International" I can easily type many accented letters. Just ' + e = é for instance. This is just like Windows. However, there I was able to type:

SHIFT + 1 = !
SHIFT + CTRL + 1 = ¡
SHIFT + / = ?
SHIFT + CTRL + / = ¿

Very convenient. But I have not been able to find a way to configure this in Ubuntu. I have to go to some site that has these symbols, and then copy-paste. Very inconvenient. Anybody any idea?

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

As for me in Ubuntu 16.04, I had to, first, configure properly the keyboard:

1. Go to "Text Entry" app by typing its name in Unity. Then make sure "English (US)" is there in the list of input sources.
2. Go to "Keyboard" app by typing its name in Unity. Then go to the Shortcuts tab, then choose "Typing" item on the left panel, then find the Compose Key row, and click on the right side where it says "Disabled" and change it to Right Alt.

From them on, these are the key shortcuts that work for me:

¿ — (holding) Alt(R) + ? + ?

(In my laptop keyboard I need to press Shift + / to actually type ?)

¡ — (holding) Alt(R) + ! + !

(In my laptop keyboard I need to press Shift + 1 to actually type !)

And for Spanish speakers, take this bonus:

ñ — (holding) Alt(R) + ~ + n

(In my laptop keyboard I need to press Shift + ` to actually type ~)

á — (holding) Alt(R) + ' + a

é — (holding) Alt(R) + ' + e

í — (holding) Alt(R) + ' + i

ó — (holding) Alt(R) + ' + o

ú — (holding) Alt(R) + ' + u