Can you make a mnemonic on how to memorize these capital cities? [10POINTS]?

There are far too many to make a mnemonic. Try writing all the capital cities & countries on separate pieces of paper & pick out at random & try to match them up. As you do this , you will quickly realise the ones that are evading your memory & can gradually cut down the number you need to concentrate on. I hope this helps , good luck in your exam.