Jump to content


Friends, we are happy to invite you to our NEW Global Kaspersky Club! Please follow this link www.kasperskyclub.com , sign-in and enjoy our new platform!


Photo

Numeric Aptitude Test


  • Please log in to reply
20 replies to this topic

#1 Jingtian

Jingtian

    Frequent poster

  • Global Moderators
  • PipPipPipPipPipPip
  • 1236 posts

Posted 09 November 2006 - 04:48 PM

A lot of multinational companies use numeric aptitude test to select candidates, but I'm not good at maths. The last time I touched maths was July 1999. Who can help me?

Here is an example:

A bag contains 12 green tokens and 8 yellow tokens. If a token is taken out at random and not replaced, then another token is taken out-

What is the probability that both tokens are green?

And if two tokens are taken out together at random, what is the probability that both tokens are green?

How to solve such difficult maths problems?

#2 Lucian Bara

Lucian Bara

    Jedi Master

  • Global Moderators
  • PipPipPipPipPip
  • 912 posts

Posted 09 November 2006 - 06:26 PM

10th grade probability problem... unfortunatly i'm past that, but
the second part is easy: "if you take them together":
the probability is: (12/20)*(11/19)
There's a forumla which should solve oyur problem no matter what the conditions...if you take the tokkens out together.

that's it in forumula.
a - category I objects.
b - category II objects
you take n (n<=a+b ) objects together, what is the probability that x are the I category and y the II category.

The probability is (see picture):

Posted Image

so you understand

C followed by the letters means combinations of that givven number-lower part takken each upper number (i'm translating mot-a-mot from romanian), which can be calculated by the following formula: C k->up, n->down: n!/(k!*(n-k)!)

As for the first part, it's a bit more difficult since the second event is conditioned by the first, i have to think about that a little longer (and force some things back into my head), but i'll let you know in the near future...
Intel Core 2 Duo E4500 @ 2,2GHz, Msi Asus P5PL2-E, 2048MB-DDR2 (2*1024), Leadtek PX6600 256MB, Teac DV-W516GA, Leadtek tv2000 xp Expert, HDD 200GB*2 (sata/sata2)

#3 Jingtian

Jingtian

    Frequent poster

  • Global Moderators
  • PipPipPipPipPipPip
  • 1236 posts

Posted 09 November 2006 - 06:46 PM

Thanks.

If the first question becomes:

A bag contains 12 green tokens and 8 yellow tokens. If a token is taken out at random and REPLACED, then another token is taken out-

What is the probability that both tokens are green?

Then is it the same as the above-mentioned Question 2?
The probability is: (12/20)*(11/19) ?

Forget about the first question in Post 1. It is too difficult for such kind of tests, as there is great time pressure. In fact, I asked the first question myself as I was curious to know how to solve that problem. I took the second question from a test paper, the first question was asked by me myself. :)

#4 Lucian Bara

Lucian Bara

    Jedi Master

  • Global Moderators
  • PipPipPipPipPip
  • 912 posts

Posted 09 November 2006 - 06:52 PM

no.
now oyu have a more possibilities depending on the tokken that's put back (yellow or green) - that's even more difficult.
Intel Core 2 Duo E4500 @ 2,2GHz, Msi Asus P5PL2-E, 2048MB-DDR2 (2*1024), Leadtek PX6600 256MB, Teac DV-W516GA, Leadtek tv2000 xp Expert, HDD 200GB*2 (sata/sata2)

#5 Whizard

Whizard

    Professional

  • Global Moderators
  • PipPipPipPip
  • 454 posts

Posted 17 January 2007 - 08:31 AM

http://www.mathgoodi...ent_events.html

You may find experiment four of use :(
Networking and Security Guru
~^Whizard^~

#6 Jingtian

Jingtian

    Frequent poster

  • Global Moderators
  • PipPipPipPipPipPip
  • 1236 posts

Posted 17 January 2007 - 04:00 PM

http://www.mathgoodi...ent_events.html

You may find experiment four of use ;)



Thanks, although it's a bit late. :(
Last Saturday, I took a written test for ANZ (Australia & New Zealand Banking Group) and I finished only about 60% of the numerical questions. To makes things worse, HSBC, Hang Seng Bank and ANZ used the same test papers. So these questions were very familiar for those who had taken the written test with HSBC and/or Hang Seng this year.

Anyway, the site you referred to is very helpful. I will benefit from it in my future written tests. :(

#7 CbIP

CbIP

    Police Officer

  • Founders
  • PipPipPipPipPip
  • 805 posts

Posted 17 January 2007 - 04:28 PM

I'm sorry! I've just found your thread - I know this sum! I've passed exam in probability theory )))
Solution:
P(A) - probability that 1-st taken token is green
P(B ) - probability that 2-st taken token is green

P(AB ) = P(A)*P(A|B )

P(A) = 12/20
P(A|B ) = 11/19

So, P(AB ) = 12/20*11/19 = 0.347

If two tokens are taken out together at random:
P(AB) = P(A)^2
Posted Image

Posted Image

Сделаю юзербар. Ask me to make userbar.
Posted Image Posted Image
Press any key - означает нажмите RESET
[md5]72dfdb13d1b60b9620fb5f1f9b163b74[/md5]

#8 Jingtian

Jingtian

    Frequent poster

  • Global Moderators
  • PipPipPipPipPipPip
  • 1236 posts

Posted 17 January 2007 - 04:58 PM

I'm sorry! I've just found your thread - I know this sum! I've passed exam in probability theory )))
Solution:
P(A) - probability that 1-st taken token is green
P(B ) - probability that 2-st taken token is green

P(AB ) = P(A)*P(A|B )

P(A) = 12/20
P(A|B ) = 11/19

So, P(AB ) = 12/20*11/19 = 0.347

If two tokens are taken out together at random:
P(AB) = P(A)^2


Thanks, now I think that sometimes learning maths is fun, with all kinds of interesting models.

#9 CbIP

CbIP

    Police Officer

  • Founders
  • PipPipPipPipPip
  • 805 posts

Posted 17 January 2007 - 06:47 PM

YEAH! Learning maths always fun!
Posted Image

Posted Image

Сделаю юзербар. Ask me to make userbar.
Posted Image Posted Image
Press any key - означает нажмите RESET
[md5]72dfdb13d1b60b9620fb5f1f9b163b74[/md5]

#10 FadeToBlack

FadeToBlack

    The Hitman

  • Members
  • PipPipPip
  • 137 posts

Posted 23 January 2007 - 12:01 AM

Not quite all the time.
Regards,
Michael

#11 Lucian Bara

Lucian Bara

    Jedi Master

  • Global Moderators
  • PipPipPipPipPip
  • 912 posts

Posted 23 January 2007 - 04:03 PM

you are learing limits now, aren't you? and probably equation systems or matrix, determinants... right?
Intel Core 2 Duo E4500 @ 2,2GHz, Msi Asus P5PL2-E, 2048MB-DDR2 (2*1024), Leadtek PX6600 256MB, Teac DV-W516GA, Leadtek tv2000 xp Expert, HDD 200GB*2 (sata/sata2)

#12 CbIP

CbIP

    Police Officer

  • Founders
  • PipPipPipPipPip
  • 805 posts

Posted 23 January 2007 - 04:53 PM

No. Now I'm learning differential equation (ALL types ), because I have an exam in a couple days!
I was learning limits at the begining of the first year education in Finance Academy!
Posted Image

Posted Image

Сделаю юзербар. Ask me to make userbar.
Posted Image Posted Image
Press any key - означает нажмите RESET
[md5]72dfdb13d1b60b9620fb5f1f9b163b74[/md5]

#13 Lucian Bara

Lucian Bara

    Jedi Master

  • Global Moderators
  • PipPipPipPipPip
  • 912 posts

Posted 23 January 2007 - 04:57 PM

i was asking FTB, I know that's what we studied in the 11th grade at about this moment, some are quite nice.
Intel Core 2 Duo E4500 @ 2,2GHz, Msi Asus P5PL2-E, 2048MB-DDR2 (2*1024), Leadtek PX6600 256MB, Teac DV-W516GA, Leadtek tv2000 xp Expert, HDD 200GB*2 (sata/sata2)

#14 CbIP

CbIP

    Police Officer

  • Founders
  • PipPipPipPipPip
  • 805 posts

Posted 23 January 2007 - 05:11 PM

OK :whistle:
Differential equation - hardcore!
But it is very interesting!
Posted Image

Posted Image

Сделаю юзербар. Ask me to make userbar.
Posted Image Posted Image
Press any key - означает нажмите RESET
[md5]72dfdb13d1b60b9620fb5f1f9b163b74[/md5]

#15 Whizard

Whizard

    Professional

  • Global Moderators
  • PipPipPipPip
  • 454 posts

Posted 15 February 2007 - 07:47 AM

Which level of Differentiation is that?
Networking and Security Guru
~^Whizard^~