A grandfather's clock chimes the appropriate number of times to indicate the hour, as well as chiming once at each quarter hour. If you were in another room and hear the clock chime just once, what would be the longest period of time you would have to wait in order to be certain of the correct time?
You would have to wait 90 minutes between 12:15 and 1:45. Once you had heard seven single chimes, you would know that the next chime would be two chimes for 2 o'clock.
You are killed in a plane crash and find yourself in front of 2 doors: one leads to heaven and one will lead you to hell for eternity. There is an identical troll at each door. You find instructions posted on the wall behind you. You can ask only one question and you can only direct it to only one of the trolls. One troll will always lie to you - regardless of your question - and the other will always tell you the truth. And only the trolls themselves know which one will lie and which one will be truthful. That is all that you are told.... What is the one and only question that will ensure you passage to heaven, and why?
Ask any of the tolls this question. "If I were to ask the other troll which is the door to Heaven, which door would he point to?" Now when the troll answers by pointing to one of the doors you simply take the other door.
There are 4 big houses in my home town. They are made from these materials: red marbles, green marbles, white marbles and blue marbles.
Mrs Jennifer's house is somewhere to the left of the green marbles one and the third one along is white marbles.
Mrs Sharon owns a red marbles house and Mr Cruz does not live at either end, but lives somewhere to the right of the blue marbles house.
Mr Danny lives in the fourth house, while the first house is not made from red marbles.
Who lives where, and what is their house made from ?
From, left to right:
#1 Mrs Jennifer - blue marbles
#2 Mrs Sharon - red marbles
#3 Mr Cruz - white marbles
#4 Mr Danny - green marbles
If we separate and label the clues, and label the houses #1, #2, #3, #4 from left to right we can see that:
a. Mrs Jennifer's house is somewhere to the left of the green marbles one.
b. The third one along is white marbles.
c. Mrs Sharon owns a red marbles house
d. Mr Cruz does not live at either end.
e. Mr Cruz lives somewhere to the right of the blue marbles house.
f. Mr Danny lives in the fourth house
g. The first house is not made from red marbles.
By (g) #1 isn't made from red marbles, and by (b) nor is #3. By (f) Mr Danny lives in #4 therefore by (c) #2 must be red marbles, and Mrs Sharon lives there.
Therefore by (d) Mr Cruz must live in #3, which, by (b) is the white marbles house. By (a) #4 must be green marbles (otherwise Mrs Jennifer couldn't be to its left) and by (f) Mr Danny lives there.
Which leaves Mrs Jennifer, living in #1, the blue marbles house.