1. General

Please answer the 11 questions

1 A bat and ball cost $1.10 in total. The bat costs a dollar more than the ball. How much does the ball cost?

2 It takes five machines five minutes to make five widgets. How long would it take a hundred machines to make a hundred widgets?

3 A patch of lily pad on a lake doubles in size every day. It takes 48 days for the patch to cover the entire lake. How long would it take to cover half the lake?

4 A person living on the ninth floor of a building always uses the lift/elevator to go to the ground floor. Except when it is raining, on returning to the building he always uses the lift/ elevator to go to the seventh floor and walks the remaining two floors to his apartment. Why?

5. Romeo & Juliet are found dead on the floor in a room. The only evidence is water & glass on the floor. How did they die?

6 A person can only count to 11 yet he/she has to check that there are 48 oranges in a box. How does he/she do it?

7 What do the numbers 3, 7, 8, 40, 50 and 60 have in common that is not true for any other numbers?

8 What is the importance of the following sequence of letters, ie O, T, T, F, F, S, S, E, N, T ?

9 Father and son are involved in an accident that kills the father. The survivor is taken to a hospital for surgery. On seeing the patient, the surgeon states, "I cannot operate on this patient as he is my son."What is the relationship of the surgeon to the patient?

10 Why are manholes round?

11 Who am I? Some clues: I was

- a successful political leader of a major world power

- one of the youngest political leaders in the nation's history

- sworn into office on a cold and cloudy day in January

- raised as a Catholic

- successful in this new position in part because of my vibrant charisma

- revered by the people

- played a critical role in a military crisis

- my name became legendary

11. The following ranking of staff member groups in the Las Vegas gambling industry is in order of descending responsibility. Now try ranking these groups in order of descending annual earnings, including tips:

i. Supervisor of dealers (overall responsibility for gambling room)

ii. Dealers (collect money for gambling chips & deals cards, etc)

iii. Cigar/cigarette sellers (sell each cigars at $25 & make $8; sell packets of cigarettes at $8 & make $3)

iv. Drink waitresses (provide free drinks to gamblers)

v. Car park attendants (park & collect cars for patrons)

vi. Call girls (hang around the casinos)

. The above questions demonstrate that we all have biases. People's attitudes and experiences can drive and frame perceptions that can lead to their reaching different conclusions from the same evidence if presented in different ways. Furthermore, our brains are still hardwired for survival.

. We recognize a piece of information as being part of a pre-existing pattern. Our bias works to short-cut thinking by unconsciously jumping ahead to a conclusion that seems plausible and probable. This works as a mental filter searching for information that supports a conclusion and rejecting any information that disagrees with our conclusion and/or leads to another possibility.

"...biases helped form our own unique view of the world. We're susceptible to our biases for three reasons: we instinctively rely on them, they're hidden and hard to identify, and we defend them subconsciously. In other words, we tend to see only what we believe. Biases are especially difficult to manage, much less overcome, because they're outside our control. We don't really play an active part in developing them; our brains do it on their own..."

Matthew May, 2005

. Our biases, especially subject matter expertise, help us think productively and solve problems. On the other hand, they can artificially limit our ability to think differently and "outside the box".

. Furthermore, mistakes can be made when using intuition alone and, often, when under pressure of incomplete information, complex problems, ill-defined goals and stress.

. Generally people are over-optimistic and over-confident. We tend to exaggerate our own ability and have delusions of control and knowledge.

Answers to the 8 questions are:

1. The ball costs $0.05 and the bat $1.05; 2. Five minutes; 3. Forty seven days; 4. Dwarf; 5; count out 11 oranges and puts 12th orange separate ‐ repeats this 4 times; 6. In word form, each comprises of 5 letters; 7. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10; 8. Mother; 9. By being round means that the round lid cannot fall into the man holes, no matter how much you twist and turn them (this is very different form square or rectangular covers); 10. Adolph Hitler (not John F Kennedy); 11. Reverse order (v, iii, iv, ii & i)

NB For the "ball and bat" puzzle - around 50% of students at Harvard, MIT and Princeton - and at the less selective universities, the number increased to 80+% - gave the incorrect answer!!!!!

"...Many people are overconfident, prone to place too much faith in their intuitions. They apparently find cognitive effort at least mildly unpleasant and avoid it as much as possible..."

Daniel Kahneman, 2012

. Is the following thinking logical?

All roses are flowers

Some flowers fade quickly

Therefore some roses fade quickly

Answer: its logic is flawed as it is possible that no roses amongst the flowers fade quickly. Need to take the time override your intuition. Many people are prone to answer questions with the first idea that comes to mind and are not willing to invest the effort needed to check their intuition. In intuition, conclusions come first and the arguments follow.

. This suggests that when people believe a conclusion is true, they are also very likely to believe the argument that appears to support it; even when these arguments are not sound.

. Failing these cognitive tests is partly due to insufficient motivation and not trying hard enough.

NB high intelligence does not make people immune to biases

(sources: Barrie Dunstan, 2006; Matthew May, 2005; Lawry Scandar, 1999; Nick Hoare et al, 1998; Malcolm Gladwell, 2008; Public Service Commission ‐ Fiji, 2013; Arthur Darrow, 2013; Daniel Kahneman, 2012)


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