Процентное соотношение трёх чисел на php

$total = $a + $b;
$apercent  = $a/$total  * 100;
$bpercent  = $b/$total  * 100;

$total = $a+$b+$c;
$apercent = ?
$bpercent = ?
$cpercent = ?

<?
$a = 30;
$b = 10;
$c = 60;
$total = $a+$b+$c;
 
$apercent = (100*$a)/$total;
$bpercent = (100*$b)/$total;
$cpercent = (100*$c)/$total;
?>
<div style="width:<? echo $apercent; ?>%; background: green; height:40px; color:#FFFFFF"><? echo $apercent; ?>%</div>
<div style="width:<? echo $bpercent; ?>%; background: #FF6600; height:40px; color:#FFFFFF"><? echo $bpercent; ?>%</div>
<div style="width:<? echo $cpercent; ?>%; background: #006699; height:40px;color:#FFFFFF"><? echo $cpercent; ?>%</div>

$apercent  = $a / $total  * 100;
$apercent  = $a * 100 / $total;
$apercent  = 100 / $total  * $a;