For the first one the pattern is multiply the previous number by five as you see 1 x 5 = 5 and so on. To keep adding to it you would do
125 x 5 = 625 625 x 5 = 3125 3125 x 5 = 15625
Now for the second one the pattern is divide the previous number by three as you can see 2187 / 3 = 729 and so on. To keep going you would
81 / 3 = 27 27 / 3 = 9 9 / 3 = 3
I hope this helps you and if you have anymore questions i'll be glad to answer them.
