There are hundreds of official and DIY IQ tests out there, but these are definitely not quizzes you can run on your lunch break.

These popular tests determine your level of intelligence, so it’s no surprise that they require you to sit for a while.

Then there’s a brief IQ test known as the Cognitive Reflection Test, consisting of just three questions.

It tests you on how accurately you can answer questions that seem simple at first but are much more complicated.

The faster you complete the test, the higher your intelligence level.

Try the world’s shortest IQ test below.

Q-1 of 3
Goal –0 out of 0

A bat and ball cost £1.10 in total. The bat costs £1.00 more than the ball. How much does the balloon cost?

### Explanation of question 1:

A bat and ball cost £1.10 in total. The bat costs £1.00 more than the ball. How much does the balloon cost?

Chances are you answered 10p for this question – we certainly did at first. This, however, is the wrong answer.

If the ball costs X and the bat costs £1 more, then it can be calculated like this:

X+£1

Therefore:

Bat+ball=X + (X+1) =1.1

Thereby:

2X+1=1.1 and 2X=0.1

X= 0.05

The correct answer is five pence.

### Explanation of question 2:

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

It’s tempting, if you answer it quickly, to guess 100 minutes.

But that’s not the right answer.

Instead, if five machines can create five widgets in five minutes, one machine will also create a widget in five minutes.

So if we have 100 machines all making widgets, they can make 100 widgets in five minutes.

This one also gives us headaches.

### Explanation of question 3:

In a lake, there is a patch of water lilies. Every day, the patch doubles in volume.

If it takes 48 days for the plot to cover the entire lake, how long would it take for the plot to cover half of the lake?

While many people could have answered 24 days, the answer is this.

If the patch doubles in size every day, it will shrink back in half. So on day 47 the lake is half full.

Of course, given the lack of verbal reasoning or any real variety of questions, it’s not the most accurate test.

So don’t feel too bad if you haven’t managed to find the right answers.

This quiz first appeared in The Mirror.

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