Answer
The number of elements belongs to at least two of these sets = 13.
Work Step by Step
From the given Venn diagram,
the regions II, IV, V, VI represents the number of elements belongs to at least two of given sets.
It's given from the Venn diagram that,
The number of elements belongs to region II = 1
The number of elements belongs to region IV = 2
The number of elements belongs to region V = 7
The number of elements belongs to region VI = 3
Therefore the number of elements belongs to at least two of these sets = 1 + 2 + 7 + 3 = 13.