80 pupils took part. 16 were Primary 5.<br><br>
&bull; Number of pupils who were <b>not</b> Primary 5 = 80 − 16 = 64<br>
&bull; Percentage not Primary 5 = \(\frac{64}{80} \times 100\%\) = \(\frac{8}{10} \times 100\%\) = 80%<br><br>
Final Answer: 80%