In how many different ways, the schedule of all exams are possible?
6
There can be two cases for the scheduled day of exams, since on every unique day of the week, there is atleast one exam:
Case I: Mon Tue Thur Sat Mon Wed Fri
This is not possible as exams end on Saturday.
Case IIMonWedFriSatTueThursSatPhyChemCompBioMathEcoEngOrChemCompPhy/MathBioEngEcoMath/PhyOrEngEconMathBioChemCompPhyOrPhy/MathEcoEngBioMath/PhyChemComp