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Combinatorics Difficulty 4.0 AMC 10/12 Find the answer Philippines
Problem:
What is the sum of all four-digit numbers that each use the digits 2,4,6, and 8 exactly once?
A number or a short expression. Fractions can be typed as 3/2, and spacing doesn't matter.
Solution
Solution:
Every digit appears in each decimal place exactly 6 times. Therefore, the sum is 6⋅(2+4+6+8)⋅1111=133,320.
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