Answer
The number of elements belongs to set B or set C but not set A =19.
Work Step by Step
From the given Venn diagram,
the regions III, VI, VII represents to set B or set C but not set A.
It's given from the Venn diagram that:
The number of elements belongs to region III = 6
The number of elements belongs to region VI = 3
The number of elements belongs to region VII = 10
Therefore the number of elements belongs to set B or set C but not set A = 6 + 3 + 10 =19.
