This IQ test only consists of 3 math questions, but very few people find the correct answer.
IQ (intelligence index) has always been a special concern of many people. However, the methods of checking or measuring this indicator are often quite complex.
To shorten this process, Professor Shane Frederick from Massachusetts Institute of Technology (USA) has launched the cognitive reflex test (IQ test) including 3 extremely short mathematical questions. There were 3,000 participants in this test, including many students from Yale University and Harvard University, and surprisingly only 17% of them gave the correct answer.
The three questions are respectively:
1. A stick and a ball cost a total of $ 1.10. The bat costs $ 1 more than the ball. How much does the ball cost?
2. There are 5 machines in 5 minutes to create 5 widgets, so how long does 100 machines make 100 widgets?
3. In a lake, there are large duckweed, each day the duckweed has the size doubled. If it takes 48 days for these hyacinths to fully cover the entire lake, how long will it take for the hyacinth to bloom?
Only 17% of the 3000 respondents gave the correct answer. (Image source: Internet)
There are common answers that people often answer but all are wrong:
Sentence 1: 10 cents ($ 0.1)
Sentence 2: 100 minutes
Sentence 3: 24 days
The correct answer is
Sentence 1: 5 cents ($ 0.05)
Explain: Call the value of the ball X, and the stick costs more than $ 1 so we have X + 1. So we have the baseball + the ball is X + (X + 1) = 1.1 (because both have a total price of $ 1.10). . So we find X = 0.05. From that, the ball costs 5 cents and the stick costs $ 1.05
Sentence 2: 5 minutes
Explanation: If it takes 5 devices in 5 minutes to create 5 items, that means 1 machine in 5 minutes creates 1 item (each machine makes 1 item in 5 minutes). According to the hypothesis, if 100 machines work together, 1 device creates 1 item in 5 minutes. So the answer would be 100 machines that make 100 widgets in 5 minutes.
Sentence 3: 47 days
Explain: Because each day goes by, the hyacinth doubles in size. So in order to reduce the size by half (which is equal to the requirements of the test), it would have to go back one day. Therefore, duckweed covered half a lake on the 47th day, until the 48th day, with a doubling in size, it will cover the whole lake.