attempt this question quickly:
a bat and a ball cost $1.10 in total.
the bat cost $1 more than the ball.
how much does the ball cost?
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read this only after u have attempted the qn.
based on behavioural economics, principle#6: people are bad at computation.
People tend to jump quickly into intuitive answers which might be wrong.
50% of Princeton students got the answer wrong. most replied 10 cents.
attempt the question again... it's actually 5 cents.
i experimented this with few friends, none has given me the right answer.
worse of all, my youngest sister's reply was "ZERO CENTS" in her first attempt! she can go back to primary school and learn her mathematics and draw her models!

sis, if u are reading this.... pls do something to your math~~~~~

alrite back to the "inhaling ethics" - next thing to read is ethical egoism.