ChallengeMediumCounting: Inclusion–Exclusion & Stars and Bars ShareCounting: Inclusion–Exclusion & Stars and Bars · Medium problemHow many ordered quadruples (x1,x2,x3,x4)(x_1,x_2,x_3,x_4)(x1,x2,x3,x4) of integers with 0≤xi≤60\le x_i\le 60≤xi≤6 satisfy x1+x2+x3+x4=15x_1+x_2+x_3+x_4=15x1+x2+x3+x4=15?Check Show answer Walk through it step by step Practice more like this Review this concept