I tried GPT-4 via ChatGPT and it nailed it without any prompt engineering.
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Prompt: 3 hens lay 3 eggs in 3 days. How many eggs do 12 hens give in 12 days?
GPT-4:
Let's first determine how many eggs one hen can lay in 12 days.
We know that 3 hens can lay 3 eggs in 3 days. This means that each hen lays 1 egg in 3 days (3 hens / 3 eggs = 1 hen / 1 egg).
To find out how many eggs one hen can lay in 12 days, we need to multiply the number of eggs laid in 3 days by 4 (since 12 days is 4 times longer than 3 days). So, one hen will lay 1 egg * 4 = 4 eggs in 12 days.
Now, we have 12 hens. To find out how many eggs they can lay in 12 days, we just multiply the number of eggs one hen can lay in 12 days by the number of hens:
12 hens * 4 eggs per hen = 48 eggs in 12 days.
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To be completely fair, this math problem can be googled, so it is probably in the training set.