 
<translate> Wata hanya: Duk wani harafi (x, y, z, w, p, q) za a iya haɗa shi ko a'a. Saboda haka, muna da 2 ^ 6 haduwa - 1 fanko haduwa = 63 haduwa A karshe amsar: (D). <eng> Another way: Any letter (x, y, z, w, p, q) can be included or not. So, we have 2^6 combinations - 1 empty combination = 63 combinations The final answer: (D). 