Interview Q&A / Aptitude

1. At what time between 4 and 5 o'clock are the hands of a clock together?

   At 21 9/11 minutes past 4 (about 4:21:49). At 4:00 the minute hand is 120 degrees behind, and it gains 5.5 degrees a minute, so it catches up in 120/5.5 = 240/11 = 21 9/11 minutes.

   IntermediateQuick answer1 min read
2. Which is the next year after 2025 that will have exactly the same calendar as 2025?

   2031. Two years share a calendar when they start on the same weekday and are both leap or both non-leap. Adding odd days from 2025 onward (1, 1, 1, 2, 1, 1) reaches 7 after 2030, so 2031 starts on the same day as 2025 (Wednesday) and is also a non-leap year.

   IntermediateQuick answer1 min read