Soal1

<?php
$person = [
    [
        "first_name" => "eko",
        "middle_name" => "kurniawan",
        "last_name" => "khannedy"
    ],
    [
        "first_name" => "mohammad",
        "middle_name" => "zuz",
        "last_name" => "ubaidillah",
        "alamat" => [
            "lokasi" => ["b13", "no 14"],
            "kecamatan" => "jombang",
            "kabupaten" => "jombang",
            "provinsi" => "jawa timur"
            ]
        ]
    ];

foreach ($person as $index => $item) {
    $nomorUrut = ($index + 1);
    $firstName = $item['middle_name'];

    if (isset($item['alamat'])) {
        $alamat = $item['alamat']['kecamatan'] . ', ' . $item['alamat']['kabupaten'] . ', ' . $item['alamat']['provinsi'];
    } else {
        $alamat = 'alamat tidak diketahui';
    }

    echo "$nomorUrut $firstName, $alamat" . PHP_EOL;
}