The Three Fundamental Questions By Brian Simpson

     We here, to relieve the high tensions of journalism, deadlines and all that exciting stuff at the bullpen, to get the freshest, juiciest articles to you, sometimes need to cool our brains down. So, we send each other logical and mathematical puzzles, to rattle the old neurons, and shake off the mental rust:
  https://www.news.com.au/finance/work/careers/the-threequestion-iq-test-fewer-than-one-in-five-people-can-answer-correctly/news-story/68086e096a7650356a3f87bebd134c2c
  https://pubs.aeaweb.org/doi/pdfplus/10.1257/089533005775196732

(1) A bat and a ball cost $1.10 in total. The bat costs $1.00 more than the ball. How much does the ball cost? _____ cents?

(2) If it takes 5 machines 5 minutes to make 5 widgets, how long would it take 100 machines to make 100 widgets? _____ minutes?

(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? _____ days?

     Interestingly enough, most people go with intuition, and get these wrong. Take problem (1), the best known. People firing from the hip give an answer of 10 cents, which is wrong as the difference between S1.00 and 10 cents is 90 cents. The answer is 5 cents. So, how does one deal with these sort of trick problems? Don’t rush in. Don’t go by intuition. If one has elementary mathematical knowledge, one should model the problem with a set of simultaneous equations. In the lake problem, that makes use of the basics of exponential growth, so at day 47, if another doubling occurs, the lake is covered. Such is the magic of exponential growth. In short, intuition and fast thinking lets us down, but most IQ tests are based on the need for speed, and good guess work, rather than the sort of thinking that science requires. 

      Oh, and some think that this can show the difference between people who are atheist (analytic thinkers) and those who believe in God (intuitive thinkers). I doubt it, since it rules out a reasoned approach to the existence of God.
  https://bigthink.com/praxis/a-three-question-math-quiz-that-predicts-whether-you-believe-in-god