Answer:
We are given with a Venn diagram.
In Venn Diagram,
S represent Swam
C represent Built Sandcastles.
n( S - (S∩C) ) = 6
n( C - (S∩C) ) = 4
n( S ∩ C ) = 15
To find: P(S) , P(C) , P(S or C, but not Both) = P((S∪C) - (S∩C)) , P( S ∪ C ) ,
P(S ∩ C) , P(C , but not S ) = P(C - (S∩C))
n(S) = n( S - (S∩C) ) + n(S∩C) = 6 + 15 = 21
n(C) = n( C - (S∩C) ) + n(S∩C) = 4 + 15 = 19
n(S∪C) = n( C - (S∩C) ) + n( S - (S∩C) ) + n(S∩C) = 6 + 4 + 15 = 25
Now, 





Therefore, Match the answers as above.