what is the formal process of amending the constitution? and why was the process designed this way?

Answer 1

Wow -- you're really trying to get us to do your homework.

How about you look up the constitution and read it -- it's something every citizen should do at one point or another.

Answer 2

To amend the Constitution you need a referendum. The referendum must be passed by a majority of the electors in the country AND a majority of the electors in a majority of the states. It was designed this way so that the larger states would not overwhelm the smaller states.

Unless you are asking about a country that is not Australia.