posted by Sarah .
Parks A survey of 300 parks showed the following.
15 had only camping.
20 had only hiking trails.
35 had only picnicking.
185 had camping.
140 had camping and hiking trails.
125 had camping and picnicking.
210 had hiking trails.
Find the number of parks that
a) had at least one of these features.
b) had all three features.
c) did not have any of these features.
d) had exactly two of these features.