Question

1- Quantos são os anagramas da palavra Cristal que começam por vogal?

Answer 1

$\boxed{\begin{array}{l}\sf Fixando~uma~vogal~temos~5~letras~para~permutar\\\sf como~essas~vogais~s\tilde ao~no~total~de~2\\\sf multiplicamos~as~permutac_{\!\!,}\tilde oes~por~2\\\sf resultando~em~240.\end{array}}$

$\boxed{\begin{array}{l}\sf\underbrace{\sf\boxed{\sf I}CRSTAL}_{\sf2\cdot P_5}=2\cdot5!=2\cdot 120=240~anagramas\end{array}}$