Out of the 80 students who took the biology exam, only 2/5 of them managed to score 100%. If a score below 80% qualified as failing, and 50 percent of the remaining students who didn't score 100% managed to score over 80%, calculate the number of students who failed the exam.
The number of students who scored 100% is 2/5*80 = 
<gadget id="calculator">2/5*80</gadget>
<output>32</output>
32.
Out of the 80 students, 80-32 = 
<gadget id="calculator">80-32</gadget>
<output>48</output>
48 did not score 100%.
If 50% of the students who did not score 100% managed to score over 80%, then 50/100*48 =
<gadget id="calculator">50/100*48</gadget>
<output>24</output>
24 students scored over 80%
The number of students who failed is 48-24 = 
<gadget id="calculator">48-24</gadget>
<output>24</output>
24.

<result>24</result>