Randomized texts

Sometimes you don't want to specify numbers but want to describe the task using text.

This can be randomized using a random index for access to a template list. The list contains factors and textual descriptions of these factors.

Question variables

template: [
  [ 2, "auf das Doppelte erh&oumlht" ], 
  [ 1.1, "um 10% erh&oumlht" ], 
  [ 1.5, "um 50% erh&oumlht" ],
  [ 0.5, "auf die H&aumllfte vermindert" ], 
  [ 0.9, "um 10% vermindert" ] 
];

Let's say you have a quantity L.

• Li is the random list index.
• Ltext is the text to be used in the question text.
• Lfactor is the factor represented by the text.

Now assume that the result is proportional to the square root of L.

• Lauf is to how many % the result changes.
• Lum is by how many % the result changes.

It is not recommended to randomize also the question of 'to' or 'by', because this might get complicated with feedback.

Lexp: -0.5; 
Li: rand(length(template))+1;
Ltext: template[Li][2];
Lfactor: template[Li][1];
Lauf: Lfactor^Lexp*100;
Lum: (Lfactor^Lexp-1)*100;

Question text

<p>Um wieviel % (mit Vorzeichen) ändert sich die Eigenfrequenz eines mathematischen Pendels,</p>
<p>a), wenn die Länge {@Ltext@} wird? [[input:ans1]]% [[validation:ans1]] [[feedback:prt1]]</p>

Input and PRT

Use Lauf or Lum as model solution and teacher's answer, depending on what your actual question was.