Try to answer the three-question quiz the co-founder of $2.8 billion startup Slack once asked every new hire

Tech companies are famous for the mind-twisting interview questions they ask job applicants.

But to judge by a quiz favored by the co-founder of enterprise communications startup Slack, which is valued at $2.8 billion, it seems that the bar for non-technical knowledge at hot startups is much lower.

In an interview with the New York Times on Sunday, Slack co-founder and CEO Stewart Butterfield revealed the three questions that he once asked all job applicants. The questions were meant to cover three disciplines - math, geography and history - in order to gauge their interest the world, he said.

Here's the quiz:

1. What is 3 x 17?

2. Name three countries in Africa?

3. What century was the French Revolution in?

To anyone with a liberal arts education, this quiz appears head-smackingly easy. But Butterfield says it's astonishing how many people are unable to answer question number 2 correctly. And when it comes to Marie Antoinette and the storming of the Bastille, Butterfield told applicants that acceptable answers could "give or take 200 years."

"I didn't expect people to get the answers right, but I just want them to be curious about the world," he says.

In any case, Butterfield says he no longer uses the three-question, multi-disciplinary quiz and now has a new question for anyone who wants to work for him:

I don't do that anymore, but I do ask everyone what they want to be when they grow up. Good answers are usually about areas in which they want to grow, things they want to learn, things that they feel like they haven't had a chance to accomplish yet but want to accomplish. A very short answer to that question would be automatically bad.