P(proper size wrench) = 0.95
P(correct number of screws) = 0.85
a) P(proper size wrench and correct number of screws) = P(proper
size wrench) * P(correct number of screws)
= 0.95 * 0.85
= 0.8075
b) P(either the proper size wrench or the correct number of
screws, but not both) = P(only proper size wrench) + P(only correct
number of screws)
= (P(proper size wrench) - P(proper size wrench and correct number
of screws)) + (P(correct number of screws) - P(proper size wrench
and correct number of screws))
= (0.95 - 0.8075) + (0.85 - 0.8075)
= 0.185
