This poll has ended. Please check the results and the explanation below:

  • $ 0.05 = 68%
  • $ 0.10 = 27%
  • $ 0.15 = 3%
  • $ 0.20 = 2%

Now, this seems like an easy one, but let’s tackle it algebraically:

(1) bat + ball = $1.10
(2) bat - ball = $1.00

Summing equations (1) and (2), we get:

(3) 2 * bat = $2.10

So, the bat costs $1.05. And the ball, by extension, costs $0.05. The answer is (a).

Easy.

Or not, apparently. One third of respondents got this one wrong. What’s more, almost all of them thought the answer was (b) $0.10.

So, what’s going on here?

Well, the bat and ball question is taken from a cognitive reflection test (CRT). CRT questions are designed to trick you, leading you towards a gut reaction that is incorrect. To be successful in a CRT, you need to overcome your cognitive biases and engage in more critical, analytical thinking.

So, well done if you got this one right – but don’t feel too bad if you didn’t.

Do you want to learn more about Cognitive Biases? Read more here.