Question 987726
<pre>
{{{4/5}}} of the pupils who took the exam passed. 

So {{{1-4/5=5/5-4/5=1/5}}} failed

18 pupils failed. 

So if there are N pupils, then since 1/5 failed,

{{{1/5}}}N = 18

Multiply both sides by 5

N = 90

how many pupils passed?

90 - 18 = 72.

Edwin</pre>