Wednesday, 13 May 2009

Not As Clever As We Think

Idle spent his afternoon in the great city yesterday, being entertained by one of the world's largest fund managers.

They started us off with an amusing talk by a fellow called Montier who is a behavioural scientist and makes a living in the city by forecasting index movements according to his knowledge of herd activity, overconfidence etc.

Some of his examples were interesting. Here are some easy questions; see how you do when the answers come up later. DON'T READ THE COMMENTS UNTIL YOU HAVE ANSWERED THEM.

1. Linda is 31, single, outspoken and very bright.
She read philosophy at university.
As a student she was deeply concerned with issues surrounding equality and discrimination.
Is it more likely that Linda:
a) Works in a bank
b) Works in a bank and is active in the feminist movement

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

3. If it takes 5 machines 5 minutes to make 5 widgets, how long would it take 100 machines to make 100 widgets?

4. 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 the lake?


Tuscan Tony said...


1 - b

2 - 5c

3 - 5 mins

4 - 47 days

Truth to tell I remember the answer to No. 4 from a while back, I'd be cheating to pretend otherwise. Let me guess the prize - you get to help idle put up the summer marquee.

Nick Drew said...

answer to (1) must surely be a(X is a less demanding spec than X and Y, therefore more likely to be met)

and I thought you were in insurance TT !! (which risk would you charge more for?)

idle said...

Indeed, Nick. It cannot be B. Think of a venn diagram, Tuscan. The overlap can NEVER be bigger than the circle.

Tuscan Tony said...

Idiot - on re-reading, of course, the b option is a subset and refinement of a. How many months have 28 days type of thing. *retreats to the back of the class*

Anonymous said...

Bill (not quango)

Got them all correct but must admit remembered two from a way back. As for 1 initially and correctly went for a on the basis that there must be more female bankers than female bankers who are feminists and thought from probability theory you multiply two probabilities for two components and get a smaller one. Then I thought wait a minute, is this a Bayesian situation. But then I don't fully understand Bayesian probability and reverted to the vanilla option.

Nick Drew said...

incidentally, qn 4, it must have been a b****y small patch to begin with, (or a rather large lake) because 2-to-the-power-48 is, errr ...

idle said...

I based the question on my own lake, nick. No taxpayers have been charged for the upkeep, dredging and stocking of trout.

electro-kevin said...

I'll get my coat.

Scrobs... said...

Three out of four, but the Feminist Movement Political Influence floored me I have to admit!

Every lady I meet who works in a bank is so s*** scared at the moment tha she'll join anything...

And that goes for estate agents too.

(Elecs, you took my coat...)

lilith said...

Nah, Scrobs, the first one was easy, but I got No.2 wrong so I guess I would never make a good banker.

Philipa said...

1 a.
2 5c.
3 5 mins.
4 47 days.

Anonymous said...

Evening Idle, Farqs here
Far too easy......and obvious in all cases!
Montier (assuming the SG man) is a very interesting, articulate and provocative strategist. One of the "must not miss" pieces every month.
Looking forward to Saturday :)

rvi said...

I just lerv these interleckchul puzzles.

1. How long is a piece of string?
2. What does that have to do with the price of eggs?
3. When will "quantitative" finally consider itself "eased"?

For No4, I heard that as a kid, but the question then was in reverse ie a frog starts from a lily pad in the centre of the pond and each day jumps half way towards the wall at the edge. How long will it take him to reach the side of the pond?

Calfy said...

Tried them on my charges last night at supper. I advised them that they were questions grown-ups often got wrong beforehand, so they were expecting a trick, but they got them all right very quickly between them. They must be easier for children than for overconfident herds of fund managers.

idle said...

I told you they were the EASY ones, troops, so don't go patting yourselves on the back too hard.

Were it not for the fact that, after 17 years of trying, I finally won the Turf Club Spring Goff meeting (where were you, farqs?), I would post the second, trickier, poser.

But I have Lady Idle to entertain, and a tough day at Newbury tomorrow after a morning spent in the Berry Bros factory outlet in Basinstoke.

Newbury - tips pls, farqs.

Gosh this idleness can be wearing sometimes.

Thud said...

Now I know why I've spent my life digging holes or hitting people for a living.