In how many ways $5$ different rings can be worn on $4$ fingers ?
Although these is similar question here In how many ways $3$ different rings can be worn in $4$ fingers with at most one in each finger?
But I want to answer it in different way which is like take $4$ fingers like $a,b,c,d$. Now $a$ can be filled in $5$ ways and so are others. So total ways are $5^4$ but answer is $4^5$. What is wrong in my reasoning? Which cases have I left out?