Given:
A=a,b,c,d
And,
R=(a,b),(b,c)
For symmetric relation, we must add (b,a),(c,b).
So, R=(a,b),(b,a),(b,c),(c,b).
For transitive relation, we must add
(a,c),(b,b),(c,a),(a,a),(c,c)
Hence,
R=(b,a),(c,b),(a,c),(b,b),(c,a),(a,a),(c,c),(a,b),(b,c)
So, number of new elements added=7