Let G be a finite group and G1, G2 are two subgroups of G. We
say that G1 and G2 are mutually permutable if G1 is permutable with every
subgroup of G2 and G2 is permutable with every subgroup of G1. We prove
that if is the product of three supersolvable subgroups G1, G2, and G3, where Gi and Gj are mutually permutable for all i
and j with and the Sylow subgroups of G are abelian, then G is supersolvable. As a corollary of this result, we also prove that if G possesses three
supersolvable subgroups whose indices are pairwise relatively
prime, and Gi and Gj are mutually permutable for all i and j with , then
G is supersolvable.