## PREP 2014 Question Authoring - Archived

### Draggable proof - problem after student checks answer

by Murphy Waggoner -
Number of replies: 0
In the following code the student is asked to put 4 expressions in order. There are two problems with the problem when I try to run it.
1. See attached image. The choices the student makes are left on the lhs. When the student checks the answer, if it is wrong (or right), then when they try again and move something from the lhs to the rhs, they end up with more than 4 items on the rhs. And they can't get rid of them, and hence, can never get the problem right. This happens to me when I am testing it out and it happens to a student when they try it.
2. I can't get the \leq in the directions to show up as an \leq, but instead it shows up as a less than.

Thanks as always,

MEW

DOCUMENT();

"PGstandard.pl",
"draggableProof.pl",
);

TEXT(beginproblem());

$Triangle = DraggableProof([ "$$\vert z \vert - \vert w \vert$$", "$$\vert \vert z \vert - \vert w \vert\vert$$", "$$\vert z + w \vert$$", "$$\vert z\vert + \vert w \vert$$" ], # The lines below are extras and will be listed as options but not # needed for the correct answer in$CorrectProof.
# An error occurs if this is not included even when blank
[ ],

SourceLabel => "Choose from these items.",
TargetLabel => "Drag items from the left to put them in increasing order here.",
);

#########################################
###
### Question the student sees
###

BEGIN_TEXT

Place these expressions involving the modulus of complex numbers in increasing order; that is, put the least element on top and the greatest element on bottom assuming $$\ <\$$ (less than) or $$\ \leq\$$ (less than or equal) between each expression:
$PAR \{$Triangle->Print \}

END_TEXT

#############################################
#