The limiting factor is the number of hours per week, which is 24
So, if only perms are done, then $ = $80/perm x (24h ÷ 2h/p) = $80/h x 12h = $960
If only cuts are done, then $ = $25/c x (24h ÷ 0.5h/c) = $25/c x 48c = $1200
So, the student should do only cuts to make the maximum revenue.