The Big TSA 2009 Thread

Hey guys, I've been doing some questions for the TSA and have a couple on the problem solving side I can't do, I would appreciate it if anyone could help.

First question:



Second question:



I don't get the same answers as the actual answers so I just want to know how they are done.

First Question: Is that a proper TSA question? If yes, I might as well admit I´m not smart enough and cancel my application, because this is a fairly advanced propability question..

Say the weather forecast will predict rain tomorrow with the unknown propability P.
It will thus predict dry weather with the propability Q - that is: Q=1-P

Based on the task, what is predicted will happen with a propability of 9/10. So, we can conclude:
P (rain was predicted and it actually rains) = P * 9/10
AND
P (dry weather was predicted but it rains anyway) = (1-P) * 1/10

We also know that the overall chance of a rainy day is 3/4
-->
P * 9/10 + (1-P)*1/10 = 3/4
P * 9/10 + 1/10 - 1/10*P = 3/4 | -1/10
4/5 * P = 26/40 | * (5/4)
P = 130/160 = 13/16 --> D is in fact correct

Note: I used fractions on purpose since you´re not allowed to use a calculator.

There must be an easier way to that solution but I can´t find it, sorry

I should be able to help out with these. I start with the second questions though which took me 20 seconds other than the frustrating 15 minutes I spent on the first one

Second Question: You simply need to catch the question´s drift which somewhat easier when you are a keen football player. The last four teams draw all the matches they play amongst each other and lose any other. Since every endangered team will play each of the other three bottom teams twice (--> 6 matches) they will end up with 6 points each. The one team with the best or let´s say least terrible goal difference will not be relegated and stay in with only 6 points.
Answer´s therefore C

First Question: Is that a proper TSA question? If yes, I might as well admit I´m not smart enough and cancel my application, because this is a fairly advanced propability question..

Say the weather forecast will predict rain tomorrow with the unknown propability P.
It will thus predict dry weather with the propability Q - that is: Q=1-P

Based on the task, what is predicted will happen with a propability of 9/10. So, we can conclude:
P (rain was predicted and it actually rains) = P * 9/10
AND
P (dry weather was predicted but it rains anyway) = (1-P) * 1/10

We also know that the overall chance of a rainy day is 3/4
-->
P * 9/10 + (1-P)*1/10 = 3/4
P * 9/10 + 1/10 - 1/10*P = 3/4 | -1/10
4/5 * P = 26/40 | * (5/4)
P = 130/160 = 13/16 --> D is in fact correct

Note: I used fractions on purpose since you´re not allowed to use a calculator.

There must be an easier way to that solution but I can´t find it, sorry

I have attempted the 2008 TSA which is provided on the website and ended up with 43 correct responses (86%) in roughly 60 minutes. However, I have no idea whether that is a good score - or an average one. In fact, I am lacking any medium of comparison. Can anybody help me out?

If I recall correctly, they're saying that X is responsible but that Y can only effect change. In my mind, that's wrong and can be directly attacked. If X has brought about circumstances, X can only reverse those particular circumstances. Sure Y has a role to play. But not directly.

I'm not convinced, what if a boy knocks over a chair and a girl picks it up. In this case X caused something but Y reversed it with no action from X. Does this disprove your logic?

I'm not convinced, what if a boy knocks over a chair and a girl picks it up. In this case X caused something but Y reversed it with no action from X. Does this disprove your logic?

This thread makes me feel stupid

I have been getting lots of pm's about the free q&a session.

so I'll put it on here. please delete if this is not allowed.

http://www.sucedo.com/products/tsa/question-session/

Hmm...this hurts my head so early in the morning!

I'm still unsure myself but what if:
In 1832 I buy a slave but in 1833 a law is passed abolishing all slavery and therefore freeing the slave. So X (the slaver owner) created the circumstance but Y (Parliament) reversed it.
Or I buy a slave but they run away. Surely (de facto) the slave is now free without the slave owner's input. So X (the slave owner) created the circumstance but Y (the slave) reversed it.

I'm just throwing ideas around :P

Someone else who actually knows what they're talking about should give us some input!

ive just done the 2008 paper timed. i finished in time and got 42/50 which is equivilant to 84%: but i understand that certain questions are weighted more. so am i doing exceptional or just average? as in says on the tsa website that scores above 80 are exceptional.
cheetrs