Step-by-step explanation:
n=3 is basically all the electrons in the 3rd energy level, so
3s=2
3p=6
3d=10
so total equals 18 electrons
n=5, l=1, refers specifically to the 5p
p has 3 orbitals so it can fill a total of 6 electrons
n=6, l=1, ml=-1,
so this refers to the 6p and since we have ml it refers to the specific orbital.
ml refers to the formula: -l -> l.
so in this case -1,0,1 ; these three numbers correspond to the 3 orbitals in the p subshell, each one can hold 2 electrons,
Thus, in this case the answers is 2