Hi jacklynleunggg,
I'm George -- a fellow student here.
Well there are certainly times when the English word 'which' can be used to translate each of these... which, I suppose, leads to confusion because there are several meanings depending on usage.
무슨 - can mean 'what' 'what kind' 'what sort' and can also mean 'anything' or 'everything'
its close synonym is
어떤 - more specifically carries the meaning 'what kind of' or 'which of many kinds''
a slightly more distant synonym is
어느 - means 'which one' 'either/neither' generally giving us a choice between TWO
Now maybe Teacher Tim, or Native Korean manyakumi, will provide some sample sentences to help illustrate further