The position vectors of the vertices A, B, C of a tetrahedron ABCD are î + ĵ + k̂, î and 3î respectively and the altitude from the vertex D to the opposite face ABC meets the face at E. If the volume of tetrahedron is \(\frac {2\sqrt 2} 3\), then the length of DE is:

The position vectors of the vertices A, B, C of a tetrahedron ABCD are

1.	The position vectors of the vertices A, B, C of a tetrahedron ABCD are î + ĵ + k̂, î and 3î respectively and the altitude from the vertex D to the opposite face ABC meets the face at E. If the volume of tetrahedron is \(\frac {2\sqrt 2} 3\), then the length of DE is:
A.	1
B.	2
C.	3
D.	4
Answer» C. 3