Răspuns:
9. a) A∪ B= { 1,3,4,5,6,7, 8,9 }
A∩ B= { 6}
10 . fie baietii B= {B1, B2, B3, B4, B5, B6, B7, B8, B9}
fete F= {F1, F2, F3, F4, F5, F6, F7, F8, F9, F10}
perechi (B1, F1 ); ( B1, F2); ( B1, F3) ; (B1, F4); (B1, F5); (B1, F6) ; (B1, F7); (B1, F8); (B1,F9); (B1, F10) - 10 PERECHI
(B2, F1); (B2, F2) ; (B2, F3).....(B2,F10) 10 PERECHI
(B3, F1);...(B3, F10) -10 PERECHI
(B4, F1)...(B4, F10) - 10 PERECHI
(B5,F1)...(B5, F10) - 10 PEPECHI
(B6, F1) ...(B6, F10) - 10 PERECHI
(B7, F1)...( B7, F10) - 10 PERECHI
(B8, F1)... (B8, F10) - 10 PERECHI
(B9, F1)...(B9, F10) - 10 PERECHI
TOTAL = 90 PERECHI
11. Ionel = 47+13= 60 lei avea
Maria= 60-28= 32 lei ii ramane
12. a) Adev ; b) fals; c) adev; ; d) fals (100kg); e) adev
13. Alin are 146 lei, Bianca are de 2ori mai mult decat Alin, Cristi are 596 lei, iar Dana are triplul lui Cristi. Cati bani au cele doua fete la un loc (Bianca si Dana)?
146x2+ 596x3= 292+ 1788= 2080 lei
