Just try with:
$element = range(1, 100);
shuffle($element);
$output = array_slice($element, 0, 15);
var_dump($output);
Output:
array (size=15)
0 => int 78
1 => int 40
2 => int 10
3 => int 94
4 => int 82
5 => int 16
6 => int 15
7 => int 57
8 => int 79
9 => int 83
10 => int 32
11 => int 13
12 => int 96
13 => int 48
14 => int 62
Or if you want to use $numbersOut
variable:
$numbersOut = 85;
$output = array_slice($element, $numbersOut);
It will slice an array from 85
to the end. Remember - if you will have 90 elements in the array, this method will return just 5 elements.