(b) (i) The probability that at least one of the two shoots deploys can be found by using the formula for the probability of the union of two dependent events, which is P(A B) = P(A) + P(B|A') - P(A B). Here, A is the event that the main shoot deploys and B is the event that the secondary shoot deploys given that the main shoot does not deploy. P(A B) = P(A) + P(B|A') - P(A B) = 0.87 + (0.80 (1 - 0.87)) - (0.87 0.02) = 0.87 + 0.104 - 0.0174 = 0.9566. explain this part