Getting thrown off by a hard interview question can be frustrating. But hiring managers toss curveballs all the time.
They ask difficult questions because they want to see whether you can think on your feet and how you behave under pressure, among other things. And how you answer these queries can make or break your chances of landing the job.
To find out some of the toughest questions employers have asked, career coach Celia Currin solicited members of the Marketing Executives Networking Group(MENG) — all of whom are senior executives — to share the most difficult questions they have asked, or been asked, in a job interview.
Here are 25 of the toughest questions she collected:

1. 'How many gas stations are there in the US?' (or other tricky riddles)

Executives also mentioned these: "How many cans of Coke will be consumed on campus today?" and "How many girls in the US play softball?"
Riddles are fun to figure out when you've got all the time in the world and nobody's assessing your thought process, or judging your answer. But when you're faced with questions like these in the hot seat, it can be stressful.

2. 'Can you guess my job if I give you 10 questions?'

The executive who was thrown this curveball said he started by asking the interviewer, "What was your first job?"
He said she "loved it" because most people would ask her things like what her major was, and where she went to college, and would never figured it out.

3. 'What don't you want me to know about you?'

The executive who said he asks this tough question likes to follow up with another challenging query: "What makes you angry?"

4. 'Tell me about the last time you used your sense of humor to help defuse a potentially sticky situation at work.'

The executive who submitted this question worked for Southwest Airlines for eight years and said the company was known to ask this.
Why? Southwest looks for candidates with positive attitudes, and while you can teach someone skills, you can't teach an optimistic outlook. How you answer this question will tell them if you've got what it takes.
"I’ve been told that if you stumble on this question it is very hard to get a job at Southwest" the executive said

5. 'If you could do anything without constraint, what would that be?'

One exec said this open-ended question hits on a candidate's vision, intellect, confidence, and other behavioral tendencies all at once.
The answer, he said, reveals how the job seeker sees themselves, how they see other people, and whether they are focused on themselves, other people, or tasks.
One candidate answered it honestly by saying: "I would work for company X." The executive thanked him for being upfront and for saving them both a lof of time and money, and they parted ways.

6. What would you like to do with your life?'

At the end of the interview, one executive says he leans back and asks, "If we put aside education, experience, and the necessity to make a living, what would you like to do with your life?"

7. 'What is the one question you were hoping I wouldn’t ask?'

This question catches most people off guard, and the job candidate's answer ends up giving the hiring manager a truthful answer to the common question, "What is your greatest weakness?"
An executive who submitted this question said he typically gets one of two responses: the candidate either immediately blurts out a weakness, or they pause and respond with a thoughtful answer. "Either way I get what I wanted — a good sense of the person’s ability to think on their feet and respond in a meaningful way," he wrote.

8. 'Why are you the best candidate in the world for this job?'

This question doesn't sound difficult until you actually try to answer it.
One executive said he once asked a senior VP marketing candidate this question, and they were unable to answer it.

9. 'How many ideas can you come up with in three minutes?'

One executive said he always asks this question because it tests "whether the light goes off in the fridge when you close it."
The most impressive candidate so far was able to give 21 unique ideas.
He says this request is so difficult because it's hard for people to think of ideas on the spot.

10. 'What would you do to improve on the iPod?'

When one exec was interviewing with a leading tech compan and the iPod was still new, he liked to ask candidates how they'd improve the music player.
The key to answering a question like this is to show you have a good sense of imagination and can be creative.
"The job interview is no time to be grounded by constraints of the business," the executive wrote. "Show imagination, excitement, and an ability to think BIG."

11. 'If you're so good, how come you're so unemployed?'

Talk about getting caught off guard.
The person who submitted this query said he had recently been laid off when he was asked his question in a job interview.
Luckily, he was able to give a clear and concise response.
He explained that he had survived four of the five rounds before he was laid off, and that many other great performers like himself had been let go, as well.

12. 'If we were to ask you the most sensitive question we could, that you hope we don't, what is that question and what is the answer?'

A marketing exec said this question is asked to get a glimpse of your character — namely your self-understanding and confidence.

13. 'What's the least amount of salary you'd be happy to receive if you believe this job would be a good fit for you?'

One exec who asks this said if a candidate isn't comfortable answering, he doesn't count that against them in the job interview. However, if they do answer the question honestly, it often saves everyone a lot of time.
For instance, if you say a number that's way beyond what the company could afford, it might not work out.
But the exec notes that it isn't unusual to offer someone more than what they said when answering this question.

14. 'Doesn't this seem too junior for you?'

Don't get too cocky if you're asked this question. The hiring manager is probably just trying to figure out whether you'll be satisfied working there, or if they're going to have to replace you soon after hiring you.

15. 'Can you tell me about yourself?'

It's seems so simple, but this questions is a "killer," said one marketing exec. "I have seen it bring [long-time] executives to their knees."
Why is it so hard to answer this one? There are so many different ways to approach it — so many things you could say. And knowing what the hiring manager is hoping to hear is often impossible.

16. 'What is the country's GDP rate?'

Questions like this can be tough — and you may feel embarrassed if you don't know the answer. But chances are, the hiring manager doesn't expect you to. Rather, they may be looking to see how you respond.
Are you honest about not knowing the answer? Do you make excuses? Do you get flustered? Do you use humor? How you handle these types of questions can tell the hiring manager a lot about who you are as a person.

17. 'Explain why the Board of Directors should fire me and hire you to take my place.'

One marketing professional was asked this tricky question by the founder and CEO of a small but successful company.
Looking back, he said he believes it was designed to evaluate his selling skills and negotiating style. He thinks the CEO was also trying to figure out if he understood what it takes to run a company.
A word of caution: Tread carefully with these types of questions.

18. 'If you could change anything in your past, what would that be?'

How you answer this one will tell the interviewer a lot about your character and attitude.
It may also be an indirect way of asking about mistakes, failures, and regrets.

19. 'Do something with this paper clip.'

One executive recalled an interviewer who always kept a paper clip on hand and would randomly tell job candidates to "do something with this clip."
"The idea was to see how they reacted to strange requests and how creative they could be," she wrote.

20. 'What are some of your weaknesses?'

This is one of the most common job interview questions — and one many of us dread most.
Read about how to tackle this tough query here.

21. 'What do you want from this job and your career?'

One executive said they always ask, "What do you want from this job and your career?" to determine whether a candidate's aspirations align with the company's goals.
The question is hard because people don't know what they want: "They’ll think about how to please the interviewer, but not about what their true calling is."

22. 'If you die, what do you want written on your tombstone?'

This unusual question is used by one executive to figure out what a candidate wants their business legacy to be.
This exec explains to each candidate that he's not looking for an answer like, "Best father, husband, wife" — instead, he wants them to focus more on what he or she wants from their career, rather than their personal life.

23. 'If you were to fail at this job, discuss what vulnerabilities in your personality or history would most likely be the root cause?'

This question, like many others, is character-focused, aid one executive.
Hiring managers want to get the clearest picture they can of who you are, and how you view yourself. Your answer to this questions will tell them how confident you are in yourself and your abilities.

24. A math question.

Another executive said he ikes to come up with math questions that are actually simple, but sound complicated. He said he refuses to hire anyone who can't answer these types of questions.
"I always ask it while the candidate is pontificating," he wrote. And he typically gets one of three reactions: the candidate freezes; the person needs to be coaxed; or they "nail it without skipping a beat."
When we're in the hot seat, we're often quite nervous. So even the simplest math question can easily trip us up.

25. 'Where does your career rank in your life priorities?'

An executive who was asked this question said the employer was attempting to discern his commitment to the company.
Specifically, he felt the employer was trying to feel out whether he would be willing to work late nights or over the weekend, and how willing he would be to put work before other commitments.
Natalie Walters contributed to a previous version of this story.