Question

In how many ways can the 7 letters A,B,C,D,E,F and G be arranged so that C and E never together.​

Answer 1

first arrange these 7 letters without any constraints so the total number of ways to do this is 7!,as we have total 7 letters.

Answer 2

7p7-(7p6)×2

I hope it will be answer of your question