Finally i got solution,
SELECT NEW ST_MultiPolygon( 'MultiPolygon(((0 0, 5 0, 2.5 4, 0 0)))' )
.ST_Intersection(NEW ST_MultiPolygon( 'MultiPolygon((( 6 0, 5 4, 2 2, 6 0 )))' ))
.ST_Intersection(NEW ST_MultiPolygon( 'MultiPolygon((( 0 0, 3 2, 0 4, 0 0 )))' )).ST_AsEWKT() as Ar
FROM dummy