By examining the diagram, or working with the formula:
**u**) **×** **v****u** **×** **v** )

Fussing with math gives the same result:

| (ku)×v| = | ku| |v| sin θ = | k | |u| |v| sin θ

The magnitude is | k | times the magnitude of
**u** **×** **v**.
And the orientation of the result must be the same.
So the answer is correct.

Another fact is that,
in general,
(**u** **×** **v**) **×** **w** =/=
**u** **×** (**v** **×** **w**)

To see this, look at the diagram and mentally form the cross product
**u** **×** **v**) **w**.
Then form the cross product
**v** **×** **w**)**u** with that.