bccc48.php

<?php

function trick_or_treat($sweets, $children, $range)
{
    $hadEnoughSweets = 0;

    for ($i = 0; $i < 1000; $i++) {
        $availableSweets   = $sweets;
        $estimatedChildren = random_int($children[0], $children[1]);

        for ($u = $estimatedChildren; $u > 0; $u--) {
            $availableSweets -= random_int($range[0], $range[1]);
        }

        $hadEnoughSweets += $availableSweets >= 0;
    }

    return number_format($hadEnoughSweets / 10, 1);

}

print trick_or_treat(150, [20, 25], [5, 10]) . PHP_EOL;