<p>I think they mean it works like this,
You ace the pre-alg subsection but bomb the other two on the first test, math score 20 composite score 30
You ace Alg/coord. geom. but bomb pre-alg and trig, math score 20 composite score 29
You ace trig but fail the other two, math score 20-something composite score 31</p>
<p>Duke would superscore all of these subsections and you could end up with a 36 math score, but your composite score would still be 31 even though it would be higher if they recalculated it with a 36 math score.</p>