Which Company Asks the Toughest Interview Questions?

Want a job at McKinsey, Boston Consulting Group, or Oliver Wyman? Prepare to go through the mental wringer. These top-notch management consulting firms put up some of the highest barriers to entry through intellectually demanding interviews, according to the latest Glassdoor.com survey, Top 25 Most Difficult Companies to Interview.

The top honor for the toughest interview process went to McKinsey & Company, with an interview difficulty rating of 3.9. It was followed by Boston Consulting Company (3.8) and Oliver Wyman (3.7). Bain & Company of Mitt Romney fame placed seventh with a 3.6 difficulty rating. (To come up with the list, Glassdoor sifted through more than 80,000 interview ratings and reviews shared throughout the past year.)

Here's a sample brainteaser: How many people would use a drug that prevents baldness? That's not a question most people have thought of, or could even consider answering correctly — unless they just invented a baldness cure you're ready to patent.

Some of the other doozies job candidates reported on Glassdoor:
- There are 3 products: tomatoes, luxury cars, t-shirts. What value added tax is applied to each product type? — McKinsey & Company Junior Consultant candidate
- What is the profit potential of offering wireless internet service on planes? — Oliver Wyman Consultant candidate
- How many hotels are there in the US? — Google Product Manager candidate
- How should Shell allocate money to give to charity groups? — Shell Oil Environmental Engineer candidate
- Estimate how many windows are in New York. — Bain Intern candidate
- How many bags does Heathrow airport lose every day? — McKinsey Associate candidate

Questions such as "where do you see yourself in five years?" and "what are your strengths and weaknesses?" just don't cut it anymore. These more nuanced, problem-solving questions reflect companies' attempts to get to know job candidates beyond a resume. Managers are trying to gauge how analytical and creative prospective employees are and whether they think on their feet.

A key component of the interview process at consulting firms is the case study, descriptions of real or hypothetical business problems; candidates are asked to analyze and suggest solutions to the problems. One case study a candidate for consultant position at Bain was faced with, for example, was to assess the market structure and profitability potential of entering the gas station and convenience store business in a local area.

The list had a couple of surprises, including Teach for America, which came in at No. 16 and got a 3.4 difficulty rating. A sample interview question on Glassdoor: Your school principal is refusing to let you hold an additional tutoring session that your students desperately need because there is a pep rally. What do you say? The nonprofit organization, by the way, offers a salary range from $25,500 to $51,000, compared with the average associate salary at McKinsey of $126,400, according to the site. (It should be noted, though, that Teach for America helps its teachers with student loans.)

Sure, some companies force their employees to go through an intellectually rigorous interview process. But for many consultant-wannabes, the salaries make it worthwhile. Here are the average annual base salaries for a variety of job titles at nine companies from the list. (Data below are based on at least 15 salary reports shared by employees on Glassdoor per job title per company, as of July 26, 2012.)

McKinsey & Company
Engagement Manager: $157,400
Associate: $126,400
Business Analyst: $70,700

Boston Consulting Group
Project Leader: $156,400
Consultant: $126,600
Associate Consultant: $69,500

Oliver Wyman
Associate: $126,000
Consultant: $79,900
Analyst: $64,500

A.T. Kearney
Associate: $128,300
Senior Business Analyst: $74,400
Data Analyst: $67,900

ZS Associates
Consultant: $121,000
Associate: $71,500
Operations Research Analyst: $72,000

ThoughtWorks
Applications Developer: $86,800
Business Analyst: $80,000
Quality Assurance Analyst: $78,900

Bain & Company
Case Team Leader: $138,000
Consultant: $124,200
Associate Consultant: $66,600

Google
Product Manager: $122,000
Software Engineer: $103,700
Systems Administrator: $94,000

Unisys
Project Manager: $110,700
Software Engineer: $80,400
Consultant: $73,000