Ok so this means that the Adult weighs 4 times as much as the kids do because there is only one adult what we can do is add 4 to the total amount of kids in the elevator and subtract 1 from the adult amount, so now we have 14 kids in the elevator (however 4 of them are a adult) so that means that 4/14 is ratio of weight from adults to kids is and 4/14 can be reduced down to 2/7 Enjoy!=)
