Respostas

2014-09-04T13:21:08-03:00
(AUB) = ( A) + (B) - ( AinterB)
45 = 25 + (B) - 10
30= 25 + (B)
5 = ( B)
2014-09-04T14:19:36-03:00
Teoria dos conjuntos:

(A U B)= A+B - (A inter B)
45=25+B-10
B=45-25+10
B=30
:.