I have to find the unit rate 3\5 divided by 3\8 and ui can't figure out how you would get 3\8 to one?

If I read your question correctly

3/5 : 3/8 ----> divide each term of the ratio by 3
= 1/5 : 1/8 ---> multiply each term of the ratio by 40
= 8 : 5 ----> divide each term of the ratio by 1
= 8/5 : 1

I don't get 3/8 : 1 either.