Hard work without talent may be lame, but talent without hard work is a shame.Many of the talented people failed as they were not hard workers. Talent alone is not a guarantee to be a successful person, one has to work hard for achieving success.
Consider an example of a singer, he may be talented but there is a lot of hard work which made him a good singer. If he had the talent but had not put in any hard work he would not have become a good singer and that is a shame.
If one wants to do well in studies or anything in his life then one has to work hard to get the desired results. There is no replacement for somebody who puts everything he's got into something he desires. Apart from both talent and hard work what else is required is the passion. Don't do what other's expect you to do but do what you love to do. You will always do well in things you like so one should choose a career as per his likings, not as per others.
So apart from talent and hard work, remember the factor of passion also in whatever you do.