7 Gold Rings Puzzle

You arrive at a hotel and have 3 sets of golden rings. The first set of rings has 4 rings, the second set has 2 rings and the third only has one ring. You cannot take these sets of rings part, You cannot exchange them for a different form of currency, and the hotel clerk has no change. You want to stay at the hotel for 7 nights, and you have to pay one gold ring for each night that you stay. You cannot pay in advance, or all at once at the end of your stay. How do you pay for your 7 nights at the hotel?

Parrots and Cages Puzzle

Tina has some parrots and some cages for the parrots.
If she put 4 parrots into each cage then she will have 1 cage left.
If she put 3 parrots into each cage then she will have 1 parrot left over. How many parrots and cages does she have?

192, 021, 222, 324, 252, 627, 2 __, 9 __?

Complete the below Sequence

192, 021, 222, 324, 252, 627, 2 _ _, 9 _ _?

Put any Mathematical signs and get 6.

Put Any Mathematical signs and get 6:
1 1 1 = 6
2 2 2 = 6
3 3 3 = 6
4 4 4 = 6
5 5 5 = 6
6 6 6 = 6
7 7 7 = 6
8 8 8 = 6
9 9 9 = 6

Chain and Nail Puzzle

There is a chain nailed to the wall. The chain is 10 feet long and the center of the chain dips down 5 feet from where each side of the chain is nailed to the wall. How far are the 2 ends of chain from each other?

Band around the Earth Puzzle

The circumference of the Earth is approximately 40,000 kilometers, and someone has just made a metal band that circles the Earth, touching the ground at all locations. You come along at night, as a practical joke, and add just 10 meters to its length (one hundredth of one kilometer !) It is now one four-millionth longer, and sits magically just above the ground at all locations How far has it risen ... could a flea, a rabbit or even a man squeeze underneath it?

Grandpa's Age Puzzle

Two boys don't know age of each other, one day they met grandpa and asked him about his age. Grandpa said:"The addtion of digit in tens place and the digit in ones place of my age is equal to the subtraction of digit in the tens place and the digit in ones place of age of one of you." The two guys thought hard, but didn't figure it out. The second day, they came to ask grandpa again, grandpa said:"My age is equal to the multiplication of the addition and subtraction of your ages." The two guys could not figure it out. The third day, they came to grandpa, grandpa said:"My age = (age of one of you)*7 - (age of the other)*4" The two poor boys still could not figure it out, the forth day, grandpa said:"One of you, whose age I didn't refer to in the first day, exchange his age's digit in tens place with digit in ones place, then minus the addition of the digit in tens place and the digit in ones place, the result is equal to my age." Can you figure out grandpa's age?