WeBWorK Problems

Using binomial coefficient notation C(n,r) in answers

Re: Using binomial coefficient notation C(n,r) in answers

by Glenn Rice -
Number of replies: 0

Here is a variant of Mike's answer that will do what I think you are asking for.  This uses a loop as you said.  I used PGML for this, but you could use PG as Mike did if you must.  I highly recommend switching to PGML though as that is the modern approach.

DOCUMENT();

loadMacros(
    "PGstandard.pl",
    "MathObjects.pl",
    "PGML.pl",
    "contextIntegerFunctions.pl",
    "PGcourse.pl"
);

TEXT(beginproblem());

Context("IntegerFunctions");
Context()->variables->are(n => 'Real');

$k = random(2, 6);
$ans_str = "";
$ans_str .= "(n - $_)" for (1 .. $k);

$ans = Formula($ans_str)->with(test_points => [ map { [2 * $_] } 1 .. $k + 1 ]);

BEGIN_PGML
What is an explicit expression for [`C(n + [$k], [$k])`]?

[`C(n + [$k], [$k]) = `] [_]{$ans}{40}
END_PGML

ENDDOCUMENT();