Zacharias and Mary each asked the angel a question beginning "How". Zacharias was made silent, and Mary wasn't. What does Luke say of each?

Here is what the verses say. Zacharias asked, "How can I be sure of this? For I am an old man, and my wife is well advanced in years." (1:18). The angel answered, "I am Gabriel, who stands in the presence of God" (1:19), and "Behold, you will be silent and not able to speak until the day that these things will happen, because you didn’t believe my words, which will be fulfilled in their proper time." (1:20). Mary asked, "How can this be, seeing I am a virgin?" (1:34). The angel answered with the Holy Spirit and "the power of the Most High" (1:35), with Elizabeth, "her who was called barren" (1:36), and with "For nothing spoken by God is impossible." (1:37). Later Elizabeth says of Mary, "Blessed is she who believed" (1:45). Luke gives the angel's reason for Zacharias's silence, "because you didn’t believe my words" (1:20), and no other; Luke doesn't compare the two questions, and these notes don't weigh one against the other. Zacharias's story doesn't end in silence. When he wrote, "His name is John." (1:63), "His mouth was opened immediately and his tongue freed, and he spoke, blessing God" (1:64), and he "was filled with the Holy Spirit, and prophesied" (1:67).