Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
Fetching contributors…

Cannot retrieve contributors at this time

101 lines (93 sloc) 6.874 kb
<!DOCTYPE html>
<html data-require="math math-format word-problems">
<head>
<meta charset="UTF-8" />
<title>Ratio word problems</title>
<script src="../khan-exercise.js"></script>
</head>
<body>
<div class="exercise">
<div class="problems">
<div id="classroom">
<div class="vars">
<var id="RATIO_GIRLS">randRange( 2, 10 )</var>
<var id="RATIO_BOYS">randRange( 2, 10 )</var>
<var id="FACTOR">randRange( 2, 5 )</var>
<var id="NUM_GIRLS">RATIO_GIRLS * FACTOR</var>
<var id="NUM_BOYS">RATIO_BOYS * FACTOR</var>
<var id="TOTAL">NUM_GIRLS + NUM_BOYS</var>
</div>
<p class="problem">In <var>course( 1 )</var> class, the girl to boy ratio is <code><var>RATIO_GIRLS</var></code> to <code><var>RATIO_BOYS</var></code>.</p>
<p class="question">If there are <code><var>NUM_GIRLS</var></code> girls, how many boys are there?</p>
<p class="solution" data-forms="integer"><var>NUM_BOYS</var></p>
<div class="hints">
<p>A ratio of <code><var>RATIO_GIRLS</var></code> girls to <code><var>RATIO_BOYS</var></code> boys means that there is a group of <code><var>RATIO_GIRLS</var></code> girls for every group of <code><var>RATIO_BOYS</var></code> boys.</p>
<p>If there are <code><var>NUM_GIRLS</var></code> girls, then there are <code><var>FACTOR</var></code> groups of <code><var>RATIO_GIRLS</var></code> girls each.</p>
<p>Because we know the ratio is <code><var>RATIO_GIRLS</var>:<var>RATIO_BOYS</var></code>, there must be <code><var>FACTOR</var></code> groups of <code><var>RATIO_BOYS</var></code> boys each.</p>
<p>There is a total of <code><var>NUM_BOYS</var></code> boys in <var>course( 1 )</var> class.</p>
</div>
</div>
<div id="classroom-give-boys-ask-girls" data-type="classroom">
<p class="question">If there are <code><var>NUM_BOYS</var></code> boys, how many girls are there?</p>
<p class="solution" data-forms="integer"><var>NUM_GIRLS</var></p>
<div class="hints">
<p>A ratio of <code><var>RATIO_GIRLS</var></code> girls to <code><var>RATIO_BOYS</var></code> boys means that there is a group of <code><var>RATIO_GIRLS</var></code> girls for every group of <code><var>RATIO_BOYS</var></code> boys.</p>
<p>If there are <code><var>NUM_BOYS</var></code> boys, then there are <code><var>FACTOR</var></code> groups of <code><var>RATIO_BOYS</var></code> boys each.</p>
<p>Because we know the ratio is <code><var>RATIO_GIRLS</var>:<var>RATIO_BOYS</var></code>, there must be <code><var>FACTOR</var></code> groups of <code><var>RATIO_GIRLS</var></code> girls each.</p>
<p>There is a total of <code><var>NUM_GIRLS</var></code> girls in <var>course( 1 )</var> class.</p>
</div>
</div>
<div id="classroom-give-total-ask-girls" data-type="classroom">
<p class="question">If there are a total of <code><var>TOTAL</var></code> students, how many girls are there?</p>
<p class="solution" data-forms="integer"><var>NUM_GIRLS</var></p>
<div class="hints">
<p>A ratio of <code><var>RATIO_GIRLS</var></code> girls to <code><var>RATIO_BOYS</var></code> boys means that a set of <code><var>RATIO_GIRLS + RATIO_BOYS</var></code> students will have <code><var>RATIO_GIRLS</var></code> girls and <code><var>RATIO_BOYS</var></code> boys.</p>
<p>A class of <code><var>TOTAL</var></code> students has <code><var>FACTOR</var></code> sets of <code><var>RATIO_GIRLS + RATIO_BOYS</var></code> students.</p>
<p>Because we know that there are <code><var>RATIO_GIRLS</var></code> girls in each set of <code><var>RATIO_GIRLS + RATIO_BOYS</var></code> students, the class must have <code><var>FACTOR</var></code> groups of <code><var>RATIO_GIRLS</var></code> girls each.</p>
<p>There is a total of <code><var>NUM_GIRLS</var></code> girls in <var>course( 1 )</var> class.</p>
</div>
</div>
<div id="classroom-give-total-ask-boys" data-type="classroom">
<p class="question">If there are a total of <code><var>TOTAL</var></code> students, how many boys are there?</p>
<p class="solution" data-forms="integer"><var>NUM_BOYS</var></p>
<div class="hints">
<p>A ratio of <code><var>RATIO_GIRLS</var></code> girls to <code><var>RATIO_BOYS</var></code> boys means that a set of <code><var>RATIO_GIRLS + RATIO_BOYS</var></code> students will have <code><var>RATIO_GIRLS</var></code> girls and <code><var>RATIO_BOYS</var></code> boys.</p>
<p>A class of <code><var>TOTAL</var></code> students has <code><var>FACTOR</var></code> sets of <code><var>RATIO_GIRLS + RATIO_BOYS</var></code> students.</p>
<p>Because we know that there are <code><var>RATIO_BOYS</var></code> boys in each set of <code><var>RATIO_GIRLS + RATIO_BOYS</var></code> students, the class must have <code><var>FACTOR</var></code> groups of <code><var>RATIO_BOYS</var></code> boys each.</p>
<p>There is a total of <code><var>NUM_BOYS</var></code> boys in <var>course( 1 )</var> class.</p>
</div>
</div>
<div id="map">
<div class="vars">
<var id="SCALE_MAP">randRange( 1, 10 )</var>
<var id="SCALE_REAL">randRange( 1, 10 )</var>
<var id="FACTOR">randRange( 2, 10 )</var>
<var id="DISTANCE_MAP">FACTOR * SCALE_MAP</var>
<var id="DISTANCE_REAL">FACTOR * SCALE_REAL</var>
</div>
<p class="problem">The scale on a map is <var>SCALE_MAP</var>cm : <var>SCALE_REAL</var>km.</p>
<p class="question">If two cities are <var>DISTANCE_MAP</var>cm apart on the map, what is the actual distance in km between the two cities?</p>
<div class="solution" data-type="multiple">
<p><span class="sol" data-forms="integer"><var>DISTANCE_REAL</var></span> km</p>
</div>
<div class="hints">
<p>The scale means that every <var>SCALE_MAP</var>cm on the map corresponds to an actual distance of <var>SCALE_REAL</var>km.</p>
<p>A distance of <var>DISTANCE_MAP</var>cm on the map is the same as <var>FACTOR</var> <code>\cdot</code> <var>SCALE_MAP</var>cm.</p>
<p>The actual distance between the two cities is <var>FACTOR</var> <code>\cdot</code> <var>SCALE_REAL</var>km, or <var>DISTANCE_REAL</var>km.</p>
</div>
</div>
<div id="map-give-real-ask-map" data-type="map">
<p class="question">If the distance between two cities is <var>DISTANCE_REAL</var>km, how far apart in cm are the two cities on the map?</p>
<div class="solution" data-type="multiple">
<p><span class="sol" data-forms="integer"><var>DISTANCE_MAP</var></span> cm</p>
</div>
<div class="hints">
<p>The scale means that every <var>SCALE_MAP</var>cm on the map corresponds to an actual distance of <var>SCALE_REAL</var>km.</p>
<p>An actual distance of <var>DISTANCE_REAL</var>km is the same as <var>FACTOR</var> <code>\cdot</code> <var>SCALE_REAL</var>km.</p>
<p>The distance between the two cities on the map is <var>FACTOR</var> <code>\cdot</code> <var>SCALE_MAP</var>cm, or <var>DISTANCE_MAP</var>cm.</p>
</div>
</div>
</div>
</div>
</body>
</html>
Jump to Line
Something went wrong with that request. Please try again.