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  1. Prepare
  2. Mathematics
  3. Probability
  4. B'day Gift
  5. Discussions

B'day Gift

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56 Discussions

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  • coelho_alv
     + 0 comments
    def solve(balls):
    r = 0
    n = len(balls)
    for i in range(0, n):
        # in half of the combinations (2**(n)), each ball is not picked
        # so we can compute its aggregated contribution to the final value as
				r += 2**(n-1)*balls[i] 
    ev = r/(2**n) # expected value
    return "%.1f"%ev
`

  • dawsonjames088
     + 0 comments

    For a unique birthday gift, consider something personalized or an experience they'll never forget. It shows thoughtfulness and makes the day extra special!

    Also, have you checked out the free gifts on Temu. They have some amazing deals and offers that could be perfect for this occasion!

  • dawsonjames088
     + 0 comments

    For a unique birthday gift, consider something personalized or an experience they'll never forget. It shows thoughtfulness and makes the day extra special!

    Also, have you checked out the free gifts on Temu They have some amazing deals and offers that could be perfect for this occasion!

  • rowlandwebb
     + 0 comments

    c#

    public static double solve(List balls)

    {
    return Math.Round((balls.Sum())/2.0, 1);
}

  • daniel_v_oconnor
     + 0 comments

    Let b_i be the price written on the ith ball. Let X_i be a random variable such that X_i = b_i if the ith coin toss is heads and X_i = 0 otherwise. The expected value of X_i is E(X_i) = b_i / 2. Let X = X_1 + ... + X_n. The price of the phone is E(X) = E(X_1) + ... + E(X_n) = (b_1 + ... + b_n) / 2.

    Python code:

    return .5 * sum(balls)