If vec(P)=hat(i)+2hat(j)-4hat(k)andvec(Q)=hat(i)+2hat(j)-hat(k) then (vec(P)+vec(Q))*(vec(P)-vec(Q)) is

If vec(P)=hat(i)+2hat(j)-4hat(k)andvec(Q)=hat(i)+2hat(j)-hat(k) then (

1.	If vec(P)=hat(i)+2hat(j)-4hat(k)andvec(Q)=hat(i)+2hat(j)-hat(k) then (vec(P)+vec(Q))*(vec(P)-vec(Q)) is
Answer» 5 15 25 115 Answer :B