Find the volume of the parallelepiped whose coterminous edges are represented by the vectors
(i) `vec(a)=hat(i)+hat(j)+hat(k), vec(b)=hat(i)-hat(j)+hat(k), vec(c)=hat(i)+2hat(j)-hat(k)`
(ii) `vec(a)=-3hat(i)+7hat(j)+5hat(k), vec(b)=-5hat(i)+7hat(j)-3hat(k), vec(c)= 7 hat(i)-5hat(j)-3hat(k)`
(iii)`vec(a)=hat(i)-2hat(j)+3hat(k), vec(b)=2hat(i)+hat(j)-hat(k), vec(c)=hat(j)+hat(k)`
(iv) `vec(a)=6hat(i), vec(b)=2hat(j), vec(c)=5hat(i)`