1 1 vote closed as a duplicate of: MadeEasy Test Series 2019: Combinatory- Generating Functions Let We define Then ar is equal to. $\binom{r}{2019}$ $\binom{r}{r + 2018}$ $\binom{r}{2019 – r}$ $\binom{r}{r – 2018}$ Can anyone tell me if this type of question is in Gate 2019 syllabus or not because I have never seen such question in previous year question? If yes, then when can I learn this stuff from. Because I am unable to understand the whole solution. Combinatory discrete-mathematics generating-functions made-easy-test-series + – jhaanuj2108 724 views comment Share Follow Print 0 reply Please log in or register to add a comment.