Common Math Interview Questions

Discussion in 'Prop Firms' started by TM1982, Jun 30, 2009.

  1. TM1982


    Anyone have a list of common math/brainteaser questions that prop firms might ask?

    I seem to recall one about telling the degrees on a clock between the minute and hour hand, and also usually one about expected value.
  2. There's one about a penny rotating on its perimeter 180deg somewhere on prior threads if you want to do a search. Few others also in that thread. GL.
  3. rosy2


    you have two cubes on your desk. every day you move both cubes so that the front faces show the current day of the month.

    what digits are on the sides of the cubes to allow this?
  4. 1. how many pennies can you fill in the room you're sitting in right now? you cant estimate, u have 30 seconds

    2. imagine a cube, made of 1000 of small cubes so it's 10 by 10 by 10. how many of these cubes are facing the outside?

    3. there 3 are hats with a apple under one and you meant to pick which one. once u made you're selection, I remove one of the other two and ask you if you want to stick to your first choice or switch. what do you do and why?

    4. i have a call option maturing in one year with 0.5 delta. what's the probability it will expire in the money?

    5. you have 18 coins, one of which weighs twice as the others. you have two-side balance scale which you can use only 3 times to identify it. how do u do it?

    I've been asked all the above in interviews. they might not appear that tough, but it's a different story when you walk into a room and someone jumps on u askin what do u understand by "LTCM", "VAR", where is today's US/EUR FX is it lower than 5 months ago, whats the rate at all central banks..

    and honestly the hardest: why do u want to be a trader and why, and what makes u think u'll be good at it. - basically checking how clueless u are.
  5. I don't think this is possible with six sided cubes unless you allow six and nine to show in the same face, which would be cheating as digits, qua digits, have orientation.

    I also see little connection between any of these questions and trading ability.

    More of a trick to allow the interviewer to feel smarter than the interviewee, IMHO.
  6. Cube A: 1,2,3,4,5,6

    Cube B: 1,2,7,8,9,0
  7. ... and so how would day 7,8, or 9 show up?
  8. July 07, 17, 27, 08... etc.

    This was a guess, BTW. Not certain, but it makes sense since 1 and 2 are the only numbers which ever need to be used at the same time.

    And also assuming the cubes are interchangeable from right to left.
  9. ok, so for example, which arrangement of
    interchangeable cubes would give July 07?
  10. Oops. Now I see your point.

    Maybe just show the 7 and hide the other cube behind the desk? :(
    #10     Jun 30, 2009