Section 5.21 Exercises that are Timed

<section xml:id="exercises-timed">
  <title>Exercises that are Timed</title>

  <p>
    This is a section that merely explains and holds an <tag>exercises</tag>
    division, which will be at the level of a <tag>subsection</tag>. There is
    a <attr>time-limit</attr> attribute on <tag>exercises</tag>, set to the
    value <c>10</c>, which implies (a) the collection of (two) exercises is a
    <q>timed exam</q> when hosted on Runestone, and (b) a student will have 10
    minutes to complete the collection.
  </p>

  <p>
    Showing results, showing feedback, displaying a timer, and allowing
    pausing are all enabled by default. To disable any of these features, set
    the corresponding attributes on the <tag>exercises</tag> division,
    <attr>results</attr>, <attr>feedback</attr>, <attr>timer</attr>,
    <attr>pause</attr>, to the value <c>no</c>. As a test, we have turned off
    pausing. Don't panic!
  </p>

  <p>
    Of course, if you are not viewing this while online and hosted on a
    Runestone server, then these exercises will not look any different than in
    other places.
  </p>

  <p>
    (Since this is an unstructured division, the number of the
    <tag>exercises</tag> is not displayed when born. It does <em>have</em> a
    number, which is the same as the enclosing <tag>section</tag>. To wit:
    <xref ref="exercises-timed"/> versus <xref ref="timing-exercises"/>.)
  </p>

  <p>
    If you prefer that a given <tag>section</tag> has more than one
    <tag>exercises</tag> within it (timed or not), realize that you must then
    structure your <tag>section</tag> with a ssequence of
    <tag>subsection</tag> as peers of the multiple <tag>exercises</tag> you
    desire.
  </p>
  <exercises xml:id="timing-exercises" label="timed-exercises" time-limit="10" pause="no">
    <title>Timed Exercises</title>

    <introduction>
      <p>
        You have 10 minutes to do these exercises when hosted online on a
        Runestone server.
      </p>
    </introduction>

    <exercise label="vector-space-dimension-timed">
      <title>True/False</title>

      <idx>vector space</idx>
      <statement correct="no">
        <p>
          Every vector space has finite dimension.
        </p>
      </statement>

      <feedback>
        <p>
          The vector space of all polynomials with finite degree has a basis,
          <m>B = \{1,x,x^2,x^3,\dots\}</m>, which is infinte.
        </p>
      </feedback>

      <hint>
        <p>
          <m>P_n</m>, the vector space of polynomials with degree at most
          <m>n</m>, has dimension <m>n+1</m> by
          <xref ref="theorem-exponent-laws"/>. [Cross-reference is just a
          demo, content is not relevant.] What happens if we relax the
          defintion and remove the parameter <m>n</m>?
        </p>
      </hint>
    </exercise>

    <exercise label="multiple-choice-not-randomized-timed">
      <title>Multiple-Choice, Not Randomized, One Answer</title>

      <idx>stop signs</idx>
      <statement>
        <p>
          What color is a stop sign?
        </p>
      </statement>
      <!-- to appear as problem with potentially multiple correct -->
      <!-- answers (even though there is only one), use           -->
      <!--                                                        -->
      <!--     <choices multiple-correct="yes">                   -->
      <!--                                                        -->
      <choices>
        <choice>
          <statement>
            <p>
              Green
            </p>
          </statement>

          <feedback>
            <p>
              Green means <q>go!</q>.
            </p>
          </feedback>
        </choice>

        <choice correct="yes">
          <statement>
            <p>
              Red
            </p>
          </statement>

          <feedback>
            <p>
              Red is universally used for prohibited activities or serious
              warnings.
            </p>
          </feedback>
        </choice>

        <choice>
          <statement>
            <p>
              White
            </p>
          </statement>

          <feedback>
            <p>
              White might be hard to see.
            </p>
          </feedback>
        </choice>
      </choices>

      <hint>
        <p>
          What did you see last time you went driving?
        </p>
      </hint>

      <hint>
        <p>
          Maybe go out for a drive?
        </p>
      </hint>
    </exercise>
  </exercises>
</section>