For two sets A and B let A Delta B denote the set of elements which belong to A or B but not both If...........

Quantitative Aptitude ( CCS) Set theory

For two sets A and B, let AΔB denote the set of elements which belong to A or B but not both. If P = {1,2,3,4}, Q = {2,3,5,6,}, R = {1,3,7,8,9}, S = {2,4,9,10}, then the number of elements in (PΔQ)Δ(RΔS) is