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2 riddles

  • 08-12-2012 10:53AM
    #1
    Closed Accounts Posts: 6,075 ✭✭✭


    Can anyone solve these riddles?

    - Russian Roulette - 4 blanks 2 bullets, all in a row. If someone shoots a blank next to you, would you take another shot or spin. Work out the probability.

    - A Bat and a Ball cost a total of £1.10, if the bat costs £1 more than the ball what is the cost of the ball.


Comments

  • Posts: 951 ✭✭✭ [Deleted User]


    A bat and a ball- The ball costs £0.05 (£1.05 + £0.05 = £1.10)
    Russian Roulette- If you took another shot then you would have 2 out of 5 chance of getting a bullet, if you spun then you would have a 2 out of 6 chance of getting a bullet, because you have the chance of getting an empty/used bullet that you couldn't have got in the first way.


  • Closed Accounts Posts: 6,075 ✭✭✭IamtheWalrus


    ft9 wrote: »
    I'm guessing it doesn't matter if you take another shot or spin as the probability is the same, 1 in 3 chance?

    The ball costs 5p.

    How did you work out the 5p?


  • Registered Users, Registered Users 2 Posts: 4,408 ✭✭✭ft9


    How did you work out the 5p?

    The ball cost 5p, the bat cost 1pound more which is 1.05. 1.05 + .05 = 1.10

    Sorry I deleted my post as it was 1st time posting here and thought I should have used spoilers.


  • Registered Users, Registered Users 2, Paid Member Posts: 3,593 ✭✭✭davetherave


    Bat and ball are 1.05 and 0.05.
    I am thinking that it is not as simple as 2/5 or 40% chance of getting shot. The person next to you fired a blank therefore you only need to account for 1 live round if they are in order 4 blanks and 2 live?


  • Posts: 951 ✭✭✭ [Deleted User]


    How did you work out the 5p?


    so £1.10 = the price of the ball + the price of the bat
    The price of the bat = £1 + the price of the ball

    so £1.10 = the price of the ball + ( £1 + the price of the ball)
    £1.10 = 2(the price of the ball) + £1
    £0.10 = 2(the price of the ball)
    £0.05 = the price of the ball


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  • Registered Users, Registered Users 2 Posts: 391 ✭✭twerg_85


    If you shoot, 3/4 chance of getting blank next, 1/4 chance of bullet.
    If you spin, 4/6 chance of blank, 2/6 chance of bullet.

    don't spin ... or better yet, don't play in the first place :)

    f.


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