Open in App Suggest Corrections 5
The miscalculation is here:
I assume your ${2\choose 1}$ implies you are choosing from $G$ and $T$ and ${4\choose 2}$ implies you are choosing 2 letters from $M,N,A,E$. Your ${4\choose 2}$ is correct, since you will get two groups of two alike letters, consequently total $4$ letters. However, your ${2\choose 1}$ is not correct (it must be ${4\choose 1}$), because you can choose not only from $G$ and $T$, but also from the remaining two letters of $M,N,A,E$. Because, a single letter will be a different (unlike) letter. All the rest is fine. |