Correct this puzzle in 5s, you are 50% better than Harvard students

The set of 3 quizzes is as easy as candy, but it turns out that more than half of the students at the world's top universities make a mistake.

The fact has proved that it is not necessarily difficult puzzles that are difficult. Sometimes, puzzles look very simple, easy to solve, but we still go wrong, for example, the puzzle below.

Don't believe it? Try solving this puzzle in 5s.

Buying a pestle and a ball costs a total of 1.1 USD. The price of the pestle bigger than the ball is 1 USD. Ask the ball how much money?

How long does it take you to solve this problem?

How many quick replies?

5

4

3

2

first
Solve it yet? The answer is 0.1 USD, right?

Sorry, sorry.The correct answer is 0.05 USD.

Set any calculator:

Suppose the ball costs X dollars, so the pestle costs X + 1 dollars. The total amount of ball and baseball is X + (X + 1) = 1.1; So we have X = 0.05 dollars.

However, if you make a mistake, do not be sad, because this question has made up 50% of students asked at Harvard University - one of the top schools in the world.

This is the first question in the Cognitive reflection test, which consists of 3 questions that Professor Shane Frederick from Yale University (USA) has proposed since 2005. According to a survey of 3,428 people, up to 33 % answered incorrectly all 3 questions. Even, up to 83% answered at least one question incorrectly.

But not all, the first question above only gave up 50% of Harvard students. In addition, for MIT students (also one of the world's top universities), only 48% answered correctly , meaning that more than half answered incorrectly.

So why is this easy question so fooling students from the world's top universities?

According to Professor Frederick, our brain has two systems of thought. A system that allows us to think very quickly, make decisions with instinct; The other system works more slowly, relying heavily on analytical skills and effort.

Meanwhile, these questions are designed to test the ability of the brain to react so they are easy to read. When receiving easy-to-read information, our brains always work according to the first system: quick thinking and instinct . Therefore, most people answer incorrectly.

In addition, Frederick said we can improve, minimize the confusion of the brain by forcing the brain to think in a system of two.

In another study, the questions in the paper were written in a more difficult-to-read font, immediately changing results.

With more difficult to read fonts, the number of correct respondents increased to nearly 70%.

The reason is because when forced to read slowly, the brain accordingly also automatically analyzes the information, helping them make more accurate decisions.

And now, try coming up with 2 other questions ! If you answered correctly within 5 seconds, you have surpassed more than half of the students at the world's top two universities, Harvard and MIT.

1. 5 machines take 5 minutes to make 5 devices. How long will the device make 100 devices?

2. In a lake, there is a duckweed. Every day, the size of the ducklings increases twice. In 48 days, water hyacinth covered the lake surface. How long does it take for water hyacinth to cover half of the lake surface?

* Now let's think for a bit before looking at the answer.

Answer:

1. 5 machines make 5 products in 5 minutes, so 100 machines make 100 products in 100 minutes?

Time for 1 machine to make 1 product is still 5 minutes, and 100 machines only take 5 minutes.

2. It takes 48 days for the algae to cover the lake surface, so does it take 24 days to cover half of it?

Unfortunately, algae grows twice a day. By the 48th day, the algae covered the lake surface, the 47th day of the algae had to be half of the lake surface.