Răspuns:
A={1,3,5,7} B={2,4,5,7} C={4,6,7,9} M1={1,2,3,4,5,7} M2={5,7} M3={1,3} M4={2,4,5,6,7,9} M5={4,7} M6={7} M7={1,2,3,4,5,6,7,9}.
