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Solved by
Thomas W. Millett
solution: oil mogul
This problem amounts to properly defining the expected value of the well to you.
The following equation does it:
(1%) * [(1.5 - 1)] +
(1%) * [(3 - 2) + (1.50 - 2)] +
(1%) * [(4.5 - 3) + (3 - 3) + (1.5 - 3)] +
. . .
(1%) * [(150-100) + ... + (3-100) + (1.5-100)]
Each line represents your expected value from a bid of 1$, 2$, ..., 100$, respectively.
eg, consider line 2 above. if you bid $2...
With 98% probability you won't win the contract, so your profit is 0. With 1% probability, you will win something worth (150%*1) = 1.5, for which you paid 2$ With 1% probability, you will something worth worth (150%*2) = 3, for which you paid 2$
So, your goal is to maximize the following function of x, where x is your bid.
f(x) = 1% * Sum_{i = 1 to floor(x)}{ x - 1.5*i }
There's no benefit to non-integer bets, so re-write the maximization function as :
ARGMAX(k) {1% * Sum_{i = 1 to k}{1.5*i - k}}
(=) ARGMAX(k) {Sum_{i=1 to k}{1.5*i - k}} /* 1% isn't a function of k or i, so toss it */
(=) ARGMAX(k) {Sum_{i=1 to k}{1.5*i} - Sum_{i=1 to k}{k}} /* Split the summation */
(=) ARGMAX(k) {(0.75)(K)(K+1) - K^2 }} /* Closed form for summations */
(=) ARGMAX(k) {(0.75)(k)-(0.25)(K^2)}} /* Algebra */
And that function is maximized at k = 1 and k = 2.
When choosing b/w $1 and $2, you should bid $1 because of time-value, reinvestment risk, etc, of the extra dollar.
(ie, if you don't have to spend the extra $$ now, don't)
That's my solution.
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