Is the word quinze the same in Brazilian and European Portuguese?

Yes

The only difference between "quinze" in Brazilian Portuguese and Continental Portuguese is pronunciation. In Brazilian Portuguese, the final "e" is clearly pronounced as a bright "ee" [i]. In Continental Portuguese, the final "e" is "reduced," meaning it is pronounced much more softly, like a muffled [ɨ], or is almost entirely swallowed in rapid speech.

Brazilian Portuguese

1. Eu tenho quinze anos. (I am fifteen years old.)
2. O ônibus chega em quinze minutos. (The bus arrives in fifteen minutes.)
3. Eu gastei quinze reais. (I spent fifteen reais.)
4. Ele tem quinze irmãos. (He has fifteen siblings.)
5. São quinze horas. (It is 15:00.)

Continental Portuguese

1. Tenho quinze anos. (I am fifteen years old.)
2. O autocarro chega em quinze minutos. (The bus arrives in fifteen minutes.)
3. Eu gastei quinze euros. (I spent fifteen euros.)
4. Ele tem quinze irmãos. (He has fifteen siblings.)
5. São quinze horas. (It is 15:00.)