Question: Tom wants to send Sally an expensive ring through the mail because they live thousands of miles apart. The only problem is that everything sent through the mail is stolen unless there is a lock put on it. Both Tom and Sally have plenty of locks and keys but they don't have any of the same locks or keys.
How can Tom send Sally the ring without it getting stolen?
Answer: Tom puts one of his locks on the box with the ring in it. When Sally gets it she puts one of her own locks on the box and sends it back to Tom. Finally Tom takes his lock off of the box and sends it back to Sally who can then unlock her own lock and retrieve the ring.
Question: 8,549,176,320 What makes this number unique?
Answer: The said number has all the numbers from 0-9 exactly once and what is special is they are in lexicographical order of their English words. Where 8,549,176,320 becomes eight-five-four-nine-one-seven-six-three-two-zero. ... The number contains all the digits from 0 to 9.
Question: Hard, Harder, and Hardest are brothers. By age from youngest to oldest, it goes Hard, Harder, Hardest. Hard is half the age of Hardest who is 20 which means hard is 10. Harder has a two-year difference between the number of years older he is than Hard and the number of years younger he is than Hardest. Harder is closer to the age of Hard than Hardest. How old is Harder?