1. Assigning Weights to Cows:
Each cow at position n is assigned a weight hn, where h=1.000000159=1+109159. When a cow moves from position m to n, its weight changes from hm to hn.
2. Weight Change Analysis:
We need to show that moving the cows strictly decreases their total weight. Consider an interval [0,5000] without loss of generality. Suppose there are 2501 cows initially at positions 0,1,…,2500. After moving, they occupy positions 2501,2502,…,5000.
3. Initial and Final Weights:
- Initial weight: ∑i=02500hi=h−1h2501−1
- Final weight: ∑i=25015000hi=h−1h5001−1−h−1h2501−1
4. Weight Decrease Condition:
If the initial weight is greater than the final weight, we must have:
h5001−2h2501+1<0
5. **Approximating h5001:**
Using the binomial expansion:
h5001=(1+109159)5001≈1+5001⋅109159+(25001)(109159)2+(35001)(109159)3+⋯
We can show that higher-order terms are negligible.
6. Simplifying the Expansion:
- First term: 1
- Second term: 5001⋅109159=0.000795159
- Third term: (25001)(109159)2=10185001⋅2500⋅1592=0.0000003160757025
- Fourth term: (35001)(109159)3≈0.0000000001024
- Fifth term and beyond are even smaller.
Summing these, we get:
h5001<1.0007954754281025
7. **Approximating h2501:**
Similarly,
h2501=(1+109159)2501≈1+2501⋅109159+(22501)(109159)2+⋯
- Second term: 2501⋅109159=0.000397659
- Third term: (22501)(109159)2=0.00000007903472625
Summing these, we get:
h2501>1.00039773803472625
8. Combining Inequalities:
h5001<1.0007954754281025
−2h2501<−2.0007954760694525
Adding these:
h5001−2h2501+1<−1.00000000064135<−1
Thus, h5001−2h2501+1<0.
9. Total Initial Weight:
The total initial weight of the cows is:
i=1∑∞hi1=h−11=159109≈6289309
10. Weight of a Cow at 100,000,000:
Using Bernoulli's inequality and approximations:
h100,000,000>4.7910>4.793⋅4.797>109.9⋅12000>6289309
Thus, h100,000,000>159109.
Since the weight of a cow at 100,000,000 exceeds the total initial weight, it is impossible for Farmer John to get a cow to position 100,000,000.