In how many ways can a student choose (n-2) courses out of n...

We have given that 2 courses are compulsory. Total remaining courses available for selection $=\mathrm{n}-2$ and total remaining courses that can be chosen from (n-2$) courses is (n-2$ ) $-2=0(n-4)$. Thus, required number of ways $={ }^{(n-2)} \mathrm{C}_{(n-4)}=\frac{(\mathrm{n}-2)(\mathrm{n}-3)}{2}$