Eight persons namely J, K, L, M, N, O, P and Q are living in an eight-floor building with bottommost floor being the first floor while topmost floor being numbered as the eighth floor. Only one person stays on one floor. All of them belong to the same family and there is only two married couple but they have different blood groups i.e. AB+, AB-, O-, B-, A-, A+, O+, and B+. Each of them participated and obtained different grade in a competitive exam viz. A, B, C, D, E, F, G, and H but not necessarily in the same order. The grading is done in alphabetical order on the basis of their marks with top scorer obtaining A grade while the lowest scorer being given H grade.L’s maternal aunt does not live on eighth or first floor. The person who is the third lowest scorer lives on the fifth floor. K is the wife of Q and she has only one child. The person who scored sixth highest marks does not have B- blood group. The person whose blood group is AB- lives on an even-number floor. The person whose blood group is O- is an unmarried brother of Q. O is the sister-in-law of Q. L’s grandmother has only one brother. The person whose blood group is AB+ lives on the top floor. The third highest scorer lives between K and L’s grandmother. O obtained B grade and M’s husband’s brother-in-law scored the highest marks. M is the mother of Q. The person who obtained G grade has O- blood group and does not stay on the fifth floor. The person whose blood group is A+ lives on the seventh floor. N is the father of J, who is the uncle of L. K’s father-in-law obtained E grade and lives on the sixth floor. The person who obtained D grade has A- blood group and lives on the third floor. The person who scored the lowest marks lives on the first floor. Q’s child and the one whose blood group is B+ live on an even-numbered floor. L’s grandmother obtained F grade and L’s uncle is the second lowest scorer. L does not have AB- blood group.