If A + B means A is the brother of B, A - B means A is the sister of B, and A × B means A is the father of B, what is the relationship of C if A + C - B means A is the brother of C and C is the sister of B?
A committee of four members is to be formed from the following people: P, Q, R, S, and T. P and Q cannot be in the committee together. R must be included if S is included. T can be included only if R is included. Which of the following groups is a valid committee?
A family consists of a father, a mother, and two sons. The father is a lawyer, the mother is a nurse, and one son is a student while the other is a chef. Who among them is not working?