0 votes 0 votes what is the approach to solve these kind of questions??? garimanand asked Oct 2, 2018 garimanand 313 views answer comment Share Follow See all 2 Comments See all 2 2 Comments reply minal commented Oct 2, 2018 reply Follow Share ans is 560 . https://gateoverflow.in/search?q=generating+function https://gateoverflow.in/65803/find-number-integral-solutions-using-generating-function?show=65803#q65803 (how to approach) 1 votes 1 votes Soumya29 commented Oct 2, 2018 reply Follow Share $(x_1+8)+x_2+x_3+x_4 = 21\\ \Rightarrow x_1+x_2+x_3+x_4 = 13\\ \binom{4+13-1}{13}=\binom{16}{13}=\binom{16}{3}=560$ 1 votes 1 votes Please log in or register to add a comment.