In the multiplication shown below, the digits have been replaced by letters: different letters represent different digits, and the same letters represent the same digits. What was the origianl multiplication?
Consider a digital clock. The first time after midnight when the three digits are all prime numbers is 2:22 am. What is the last time before 10:00 am, when the three digits on the clock are all prime numbers?
Every hour a clock chimes as many times as the hour. For example, the clock chimes 4 times at both 4:00 am and 4:00 pm. How many times does it chime from 4:00am through 11:00 pm of the same day including 4:00 am and 11:00 pm.?