ChallengeMediumCounting: Inclusion–Exclusion & Stars and Bars ShareCounting: Inclusion–Exclusion & Stars and Bars · Medium problemHow many ordered quadruples (a,b,c,d)(a,b,c,d)(a,b,c,d) of integers satisfy a+b+c+d=20a+b+c+d=20a+b+c+d=20 with 1≤a,b,c,d≤81\le a,b,c,d\le 81≤a,b,c,d≤8?Check Show answer Walk through it step by step Practice more like this Review this concept