Question

Multimea A are 2000 de elemente si multimea B are 2019 elemente:
a) daca A reunit cu B are 2040 de elemente, cate elemente are multimea A intersectat cu B?
b) daca A intersectat cu B are 1900 de elemente, cate elemente are multimea A reunit cu B?​

Answer 1

Răspuns:

a)Card (A∩B)=1979
b)Card (AUB)=2119

Explicație pas cu pas:

Card A=2000

Card B=2019

a) Card (AUB)=2040

Card (AUB)=Card A+Card B-Card (A∩B)

=> Card (A∩B)=Card A+Card B-Card (AUB)

Card (A∩B)=2000+2019-2040=4019-2040

Card (A∩B)=1979

b) Card (A∩B)=1900

Card (AUB)=Card A+Card B-Card (A∩B)

Card (AUB)=2000+2019-1900=4019-1900

Card (AUB)=2119