This is a cool teshuva from Rav Chaim (the first one on the page) that I saw just last week, printed in Kuntris Ga'al Yisroel on Purim from Rabbi Yisroel Levovitz of Lakewood.
Rabbi Levovitz wrote to Rav Chaim that he heard from Artscroll's Rabbi Meir Zlotowitz that there are no known pessukim that begin with a פ and end with an א, so his daughter, whose name is פיגא, does not have a passuk to say for her name at the end of Shemonah Esray. He adds that there is also no known passuk for נח, so people just resort to saying אלה תולדות נח.
Rav Chaim answered matter-of-factly by simply stating two pessukim that fit the criteria perfectly! (In the footnote, Rabbi Levovitz writes that he sent the teshuva to Rabbi Zlotowitz, and Artscroll subsequently added those pessukim to their sidurim.)
This seems so simple but it's really mind-blowing. If someone asks us to find such a passuk in something we say 3 times a day in davening - it's highly doubtful any of us would be able to find it. But Rav Chaim was able to go through the entire Tanach like that and find those 2 pessukim!