! y+ n1 { V2 {- f! [8 \' FNo.11 + t% a* A% k1 M; B) G1 w# r" k(1) When events A and B are independent, P(A and B) = P(A)P(B) 9 K J" D0 `# W(2) 6 v; a: ^' {) u
7a + 77b = 350 -----> a + 11b = 50 7 x" q5 |/ n2 q8 sn = a + b = 50 - 11b + b = 50 -10b & s2 l# R' t$ K! e4 kso n = 50 or 40 or 30 or 20 or 10