MathCastle
AIMESuperchallenge

AIME · Superchallenge problem

How many ordered quadruples (a,b,c,d)(a, b, c, d) of integers satisfy 0≤a,b,c,d≤90 \le a, b, c, d \le 9 and a+b+c+d=26a + b + c + d = 26?

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