How exactly do i go about solving these questions:an example would be fine
The first one is exactly 5!, no?
Let's take a look at the second one. It starts like 8!, but that is 8*7*6*5*4*3*2*1. But the last part 5*4*3*2*1 isn't there, and that's exactly 5!. So we need 8!, but not the 5!, so 8!/5!. Check:
$\displaystyle
\frac{{8!}}{{5!}} = \frac{{8 \cdot 7 \cdot 6 \cdot 5!}}{{5!}} = 8 \cdot 7 \cdot 6
$