Answer:
14 donuts
Explanation:
Packing circles in a rectangular space is always an interesting problem. Sometimes, it works well to put them on a grid. Other times, more circles can be packed in if they are somewhat off-grid. The details depend on the specific dimensions.
The attached shows a way to fit 14 donuts in the box.
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Additional comment
Packing them on a square grid allows only 12 donuts to be put in the box.