CombinatoricsDifficulty 1.6JuniorFind the answerNetherlands
How many three-digit numbers, with each digit unequal to zero, are there such that the three digits add up to 7? A) 4 B) 7 C) 10 D) 15 E) 21
This was a multiple-choice question, but the options didn't survive into the
source we have. The answer given is D, and the solution
below works it through.
Solution
D) 15
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Source: MathNet,
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