one number is 15 and the other is 16. You get this answer by first finding a factor of 3(15) that when it's subtracted from 31 gives you a factor of 8(16). Then you divide in this case 15 by 3 and get 5 and 16 by 8 and get 2. The reason you divided the numbers is because now you have 5 which is 1/3 of 15 and 2 which is 1/8 of 16. Now that you have your numbers that equal your fractions multiply 5 which is your 1/3 by the 2 from your 2/3 to get 10 which is 2/3 of 15 and 2 which is 1/8 by the 5 from you 5/8 to get 10 which is 5/8 of 16