When the instructor went to try it out, acting as that student, they checked the answer, and it is counted correct, as seen in this screen shot.

I took it one level further and changed the seed for myself for the problem to be the same as the student has. Then I was able to submit an answer for myself, and it again is counted correct, as seen in this screen shot.

Then I took it even further, and temporarily made the student have professor level privileges. This didn't matter---the correct answer was again blocked for her.

Is there any insight into how a problem can behave differently for different users, even with the same seed? This is not the first time something like this has happened in the past year or so, even going back to when we were on the master 2.8 release.

# WeBWorK problem written by Carl Yao

# Portland Community College

#

# Compare two fractions with the same denominator.

#

# Last edited: Yao 9/26/2013

#

# ENDDESCRIPTION

## DBsubject('Algebra')

## DBchapter('Basic Algebra')

## DBsection('Algebraic Expressions')

## KEYWORDS('compare','fraction')

## DBCCSS('6.NS.7.a')

## TitleText1('')

## EditionText1('')

## AuthorText1('')

## Section1('')

## Problem1('')

## Author('Carl Yao')

## Institution('PCC')

#This command starts the problem.

DOCUMENT();

########Begin Load Macro Files############

loadMacros(

"PGstandard.pl", #Always needed

"MathObjects.pl", #Almost always needed

"PGML.pl", #Almost always needed

"contextFraction.pl", #needed to have the Fraction Math Object

"parserPopUp.pl",

"PGcourse.pl",

);

########Begin Problem Setup############

TEXT(beginproblem());

Context("Fraction");

$den = random(5,20,1);

do {$num1 = random(1,$den,1);} until (gcd($num1,$den)==1);

do {$num2 = random(1,$den,1);} until ((gcd($num2,$den)==1) && ($num2!=$num1));

$frac1 = Fraction($num1, $den);

$frac2 = Fraction($num2, $den);

Context()->strings->add('<'=>{},'>'=>{},'='=>{});

if($frac1 < $frac2)

{

$answer = String('<');

$popup = PopUp(["?", $LTS, $GTS, "="], $LTS);

}

elsif($frac1 > $frac2)

{

$answer = String('>');

$popup = PopUp(["?", $LTS, $GTS, "="], $GTS);

}

else

{

$answer = String('=');

$popup = PopUp(["?", $LTS, $GTS, "="], "=");

}

$answer='{}'.$answer.'{}';

########Begin What the Student Sees############

BEGIN_PGML

Choose [`[$LTS]`], [`[$GTS]`], or [`=`] to make a true statement.

[`` [$frac1] ``] [@$popup->menu()@]* [`` [$frac2] ``]

END_PGML

########Begin more complicated answer processing (if needed)############

ANS( $popup->cmp(correct_ans_latex_string => "$answer") );

########Begin solution.############

BEGIN_PGML_SOLUTION

These two fractions have the same denominator, so the fraction with the bigger numerator is bigger.

The answer is:

[``[$frac1][$answer][$frac2]``]

END_PGML_SOLUTION

ENDDOCUMENT();