Find the volume of the paralllelepiped determined by the vectors `bar(a), bar(b)` and `bar(c)`
`bar(a) = hat(i) + 2hat(j) + 3hat(k), bar(b) = -hat(i) + hat(j) + 2hat(k), bar(c ) = 2hat(i) + hat(j) + 4hat(k)`

Answer

9 cubic units.