You are given 5 bags. There are 10 beads in each of the bags. In four of the bags,
the beads each weigh 10 kilograms. In the remaining bag, each bead weighs
only 9 kilograms. All the bags and beads look identical.
You must find out which bag has the lighter beads. The problem is that all the bags look identical and all the beads look identical.
You can use a scale, but it has to be a single-tray scale, not a two-tray balance scale. Also, you may use the scale only once.
How can you find out which bag has the lighter beads? - Answer
You have 9 gold coins.
All 9 coins look exactly the same but one coin is a fake and is either lighter or heavier than the other 8 coins.
You have a scale - balance type with 2 trays - but can only load it twice.
How do you find the fake gold coin? - Answer
Three friends check into a motel for the night and the clerk tells them the bill is $30, payable in advance.
So, they each pay the clerk $10 and go to their room.
A few minutes later, the clerk realizes he has made an error and overcharged the trio by $5.
He asks the bellhop to return $5 to the 3 friends who had just checked in.
The bellhop sees this as an opportunity to make $2 as he reasons that the three friends would have a tough time dividing $5 evenly among them;
So he decides to tell them that the clerk made a mistake of only $3, giving a dollar back to each of the friends.
He pockets the leftover $2 and goes home for the day!
Now, each of the three friends gets a dollar back, thus they each paid $9 for the room which is a total of $27 for the night.
We know the bellhop pocketed $2 and adding that to the $27, you get $29, not $30 which was originally spent.
Where did the other dollar go? - Answer
Cathy has six pairs of black socks and six pairs of brown socks in her drawer.
In complete darkness, how many gloves must she take from the drawer in order to be sure to get a pair that match?
Think carefully! - Answer