Problem using .TrueForAll

[Scalp994]

Sorry, I couldn't even find a proper title for the question.

I've got a code that goes like this:

for(i=0 ; i <= numberofstudents ; i++)
{
//looking for the students that have chosen maths on HL among all the students
if (students[i].maths == "Higher level")
{
//checking if those students have free time on given lessons
if (students[i].mondaylesson1 == false && students[i].mondaylesson2 == false)
{
//if they do, assigning the subject to the timetable
addmathstotimetable();
numberofmathstoadd -=2;
students[i].mondaylesson1 = true;
students[i].mondaylesson2 = true;
}
}
}

The problem is, such code stops at a given "i" where the student has maths on higher level, and then checks only for him if he has those "monday1" and "monday2" lessons free. It doesn't really consider the other students that have maths on HL, because the subject is already assigned to the timetable. I figure I'd have to create a separate list of people that have maths on HL and then scan it with some .TrueForAll method, checking if ALL the people in that group have those lessons free. How exactly do I do that?