SELECT
        SUM(`Users`.`age`) AS "Total Age",
        `Users`.`name`,
        `Users`.`surname`,
        `Users`.`driver_license`,
        `Users`.`carRentDate`,
        `Cars`.`id`
FROM
    `Users`
JOIN
    `Cars` ON `Users`.`car_id` = `Cars`.`id`
WHERE
    `Cars`.`id` < 10
GROUP BY `Users`.`age`