Question 467827
1.  Correct.

2.  A, B, and C being three independent events  ==> A',  B', C' (their complements) are also independent.

==> The probability that all three parts function WITHOUT failure in their first 1000 hours of use is 0.9*0.8*0.6 = 0.432.

3.  P(E U F) = P(E) + P(F) - P(E)*P(F) = 0.4  + 0.7 - 0.28 = 0.82.