Puzzles
1.Probability of meeting
Two boys, each makes a visit to mess of the RK Hall. Each arrives at a random time between 7:00 and 8:00pm for dinner. Each one of them stays for exactly 15 minutes. On any one given night, what is the probability that they will see each other?
Tag : Probability
2.Finding Fox
There are seven holes arranged in a line. A fox hides in one of them. Each night, the fox moves to a different hole, either the neighboring hole on the left or the neighboring hole on the right. Once a day, you get to inspect one hole of your choice. How do you make sure you eventually find the fox?
Tag : Logic
3.Cracking the code
A few researchers are trying to crack a code which involves discovering the values of three integers. They know they are between 1 and 100 (inclusive), and that they may be the same.
They each have a different piece of information.
Alice knows the geometric mean.
Bob knows the arithmetic mean.
Chris knows the arithmetic mean of the squares.
They get together to share information and crack the code, but they are being very secretive in an attempt to conceal their results from anyone else. You listen in to their conversation.
Chris: " I don't know all of the numbers "
Alice: "I don't know any of the numbers "
Chris: " You didn't need to tell me that, I knew that already "
Alice: " Well now I know all the numbers! "
Chris: " I still don't know all the numbers "
Bob: " I don't know all of the numbers either "
Chris: " Argh, I still don't know all the numbers "
Bob: " Ah - now I know all of the numbers "
" A ha! " you cry. For they have accidentally revealed the numbers to you. What are they?
You should assume these researchers always tell the truth and make perfect deductions and calculations.
Tags : Programming, Logic