You've looked through your resume for the nth time to make sure it's presentable and have prepared an impressive portfolio. You've also taken pains to dress appropriately and have done extensive research on a company giving you a make-or-break interview. Nothing can go wrong at this meet-the-honchos session. Or can it?

You may think you have everything covered - until you find yourself stumped when an interviewer decides to ask you questions you have difficulty answering.

But many seemingly tough interview questions only sound challenging because you have not had the chance to think through them. If you could, wouldn't it make things much easier?

While there are no full-proof means of knowing what a decision-maker may ask, there are certainly ways to reduce the probability of failure and increase the chance of success, such as checking out these toughies first:

"Tell me about yourself"

Prepare a short statement in advance. When answering this question, make sure that it does not sound overly rehearsed. You could talk about projects you have managed and past vocations that relate to the post you are seeking.

"Why did you leave your last job?"

Give positive references and don't put the blame on your ex-bosses, management or colleagues as it'll only make you look bitter. Say instead that you left because you wanted to explore opportunities and take on new, more or different things and duties.

"Do you consider yourself successful?"

Saying yes doesn't imply that you are a proud person. Justify your confident answer by backing it up with examples of how you have mostly achieved your goals, and are on track to attain others.

"What have you done to improve your knowledge in the last year?"

Talk about improvement activities that related to your previous job. You can mention an assortment of achievements, but zoom in on a few more pertinent ones.

"Why do you want to work for this organisation?"

Answer with how you think your long-term, personal goals relate to the culture of the company and/or meet the expectations of the position you're applying for. Be sincere in your delivery.

"Do you know anyone who works for us?"

Be careful to mention a friend only if you are sure that he's well thought of in the company.

"What kind of salary do you need?"

Put the ball in your interviewer's court and ask him instead for the range offered for this position. If he doesn't budge, and you're really not sure, say that you can't give a precise figure as it depends on the job description to be agreed upon between both parties, which could be unique or customisable, depending on the needs of the company and how relevant your skills are to the post.

"Why should we hire you?"

Point out how you believe your strengths will meet the organisation's needs. Refrain from drawing comparisons with other candidates.

"If you were hiring a person for this job, what would you look for?"

Mention traits you possess that are required by the company for that position.

"Do you have any questions for me?"

Always prepare some questions, especially those that will suggest how you are able to contribute to the organisation.