Answer:
8
Explanation:
Partial order of a set:A relation R on set A is called partial order if it is reflexive,anti-symmetric and transitive.The set together with partial order R is called partial ordered set.
Partial order is the collection of subsets of set A.
A=P(S)
Power set of S=P(S)={
,{a},{b},{c},{a,b},{b,c},{a,c},{a,b,c}}
Partial order on S =P(S)=

Partial order=8
Hence, the partial order on S=8