Răspuns:
M∪P={a,b,c} → M,P⊆{a,b,c}. M∩P={b} → b∈M, b∈P.
1) Daca a∈M, atunci a∉P, altfel ar rezulta a∈M∩P. fals.
1.1) Daca c∈M, atunci c∉P. Prin urmare M={a,b,c} si P={b}
1.2) Daca c∉M, atunci c∈P, altfel c∉M∪P=A, fals. Deci M={a,b}, P={b,c}
2) Daca a∉M, atunci a∈P.
Similar cu cazul 1), avem 2.1) M={b,c}, P={a,b} sau 2.2) M={b}, P={a,b,c}
