Mathematics

Problem

Let

ABCD

be a tetrahedron such that the edges

AB

AC

and

AD

are mutually perpendicular. Let the area of

\Delta ABC

\Delta ACD

and

\Delta ADB

be 3, 4 and 5 sq units, respectively. Then, the area of the

\Delta BCD

, is a.

5\sqrt{2}

b. 5 c.

5/\sqrt{2}

\frac{5}{2}