I am reading the book David and Goliath: Underdogs, Misfits, and the Art of Battling Giants by Malcolm Gladwell and I found the following test in this book. The test is the Cognitive Reflection Test (CRT). It was invented by Yale professor Shane Frederick.
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?
And here is another one
It takes 5 machines 5 minutes to make 5 widgets,
how long would it take 100 machines to make 100 widgets?
Leave the answer in the comments