There are two rows. Each row has five blanks. The first row is 3,9,6,4,5. The second row is 6 / 18,25 / 47,17 / 31. The last two are empty. Find the rules,

There are two rows. Each row has five blanks. The first row is 3,9,6,4,5. The second row is 6 / 18,25 / 47,17 / 31. The last two are empty. Find the rules,


12/20
16/24