Answer :
She is 31
F-Faye
J-Joshua
F3-J4=31
F=J2+5
(J2+5)(3)-J4=31
J2+5=31
J2+5-5=31-5
J2=26
J2/2=26/2
J=13
F=13(2)+5
F=26+5
F=31
F-Faye
J-Joshua
F3-J4=31
F=J2+5
(J2+5)(3)-J4=31
J2+5=31
J2+5-5=31-5
J2=26
J2/2=26/2
J=13
F=13(2)+5
F=26+5
F=31