HOw to say , sure , why not~ in korean (informal way plz)

Question

HOw to say , sure , why not~  in  korean (informal way plz)

Answer

sure-물론 or 물론이지 
why not-왜 안되겠어, 당연히 되지

i think both expressions can be used in similar context.

Answer

for most situations, there isn't a good literal translation for this phrase.
do you mean as an answer to "let's go get ice cream!"? then you can say 좋아~
or do you mean as an answer to like "can children learn to surf?", then you can use the expressions lohems said.