Question 1208184
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M = visit museum
Z = visit zoo
P(M) = 0.5
P(Z) = 0.4
P(M and Z) = 0.25


Part (a)
P(M or Z) = P(M) + P(Z) - P(M and Z)  ........ inclusion-exclusion principle
= 0.5+0.4-0.25
= <font color=red>0.65</font>


Part (b)
P(neither M nor Z) = 1 - P(M or Z)
= 1 - 0.65
= <font color=red>0.35</font>


Part (c)
P(M or Z but not both) = P(M or Z) - P(M and Z)
= 0.65-0.25
= <font color=red>0.4</font>


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Summary of answers
(a) <font color=red>0.65</font>
(b) <font color=red>0.35</font>
(c) <font color=red>0.4</font>
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