Shortest IQ test in the world only has three questions but you’ll probably fail it

Many of us like to watch quiz shows on TV and think we’re the smartest people in the world, shouting at the screen as contestants repeatedly answer the easiest questions all wrong.

But deep down, we know that it’s just living room bravado and, frankly, probably a bit of fluke. Oh, and the fact that you Googled one of the questions while your other half wasn’t looking.

If you’re wanting to see how clever you really are, however, there’s a simple IQ test that really weeds out the wheat from the chaff.

The test, which was first published by professor Shane Frederick back in 2005, only has three questions.

However, in spite of its short nature, more than 80 percent of people fail it - when Frederick tested it on 3,000 participants, he found that just 17 percent managed to score 3/3.

With that in mind, let’s see how you fare...

The test only has three questions, but may leave you scratching your head for some time (Carol Yepes/Getty Images)

Question 1

A bat and a ball cost $1.10 in total. The bat costs $1 more than the ball. How much does the ball cost?

Don’t rush this one, as the answer might not always be as simple as it seems.

Question 2

If it takes five machines five minutes to make five widgets, how long would it take 100 machines to make 100 widgets?

Anyone else getting flashbacks to GCSE maths questions?

Now for the third and final question - the last one you need to get right if you want to make it into that 17 percent.

Question 3

In a lake, there is a patch of lily pads. Every day, the patch doubles in size. If it takes 48 days for the patch to cover the entire lake, how long would it take for the patch to cover half of the lake?

Can you get the hat trick to try and prove you really are are smart as you think you are?

Can I phone a friend? (Tetra Images/Getty Images)

Answers

Okay, let’s put you out of your misery and go through the answers.

Usually, people give the answers as 10 cents, 100 minutes and 24 days. If that’s what you went for, though, I’m afraid to say you’re wrong, as the answers are actually 5 cents, 5 minutes and 47 days.

Addressing the first question, Frederick explained: "Anyone who reflects upon it for even a moment would recognise that the difference between $1 and 10 cents is only 90 cents, not $1 as the problem stipulates.

"In this case, catching that error is tantamount to solving the problem, since nearly everyone who does not respond '10 cents' does, in fact give the correct response."

If you’re still a bit lost, Presh Talwalkar attempted to explain the answers in a more manageable way on his blog, Mind Your Decisions.

"Say the ball costs X,” he began.

“Then the bat costs $1 more, so it is X + 1. So we have bat + ball = X + (X + 1) = 1.1 because together they cost $1.10. This means 2X + 1 = 1.1, then 2X = 0.1, so X = 0.05. This means the ball costs 5 cents and the bat costs $1.05."

Moving onto the second question, Talwalkar continued: “If it takes 5 machines 5 minutes to make 5 widgets, then it takes 1 machine 5 minutes to make 1 widget (each machine is making a widget in 5 minutes). If we have 100 machines working together, then each can make a widget in 5 minutes. So there will be 100 widgets in 5 minutes."

And for the final challenge, he said: "Every day FORWARD the patch doubles in size. So every day BACKWARDS means the patch halves in size. So on day 47 the lake is half full."