Special Transaction

Mark went to a restaurant for dinner last night.  When he received his check he paid with a hundred dollar bill.

When the waiter returned his change, Mark received one of every denomination of currency under one hundred dollars.

What was the total cost of Mark’s meal?

View Answer
$13.59, the waiter returned to him a $50 bill, a $20 bill, a $10 bill, a $5 bill, a $1 bill, a quarter, a dime, a nickel, and a cent.

Matters that Count

Placed above, I make greater things small. Placed beside I make small things great. In matters that count, I always come first. Where others increase I keep them the same.

What am I?

View Answer
The number 1. If you put the number one above another number it turns it into a fraction.  If you put it next to another number it makes the number larger.  If you put things in order the number one comes first.  If you multiply by one the number stays the same.

Lily Pad Lake

In a lake, there is a patch of lily pads. Every day, the patch of lily pads doubles in size.

If it takes 48 days for the patch to cover the entire lake, how long would it take for the patch to cover half the lake?

View Answer
47 Days.  The next day it doubled and covered the entire lake.

Frog Escape

A frog falls down a well that is 30 feet deep. Each day he climbs up 2 feet, and each night he falls back down 1 foot. How long does it take him to climb out of the well?

View Answer
29 days! Each day he goes up 2, and each night down 1. A net gain of 1 foot. But on the 29th day he goes up the usual 2 feet, and is out of the well, so he doesn’t fall back the foot at night.

Lots of Legs

You walk into a room where there are seven girls.  Each girl has seven bags.  Inside each bag are seven adult cats.  Each adult cat has seven kittens.

Assuming no one is missing any limbs, how many legs are in the room?

View Answer
The seven girls have a total of 14 legs. There are 343 adult cats and 2410 kittens for a total of 10976 legs.  You walked into the room, so that is two more legs for a grand total of 10992 legs.

Boxes of Balls

There are two boxes, box A and box B.  Each box contains several balls.

If you move one ball from box A to box B, box B will then have twice as many balls as box A.

If you move one box from box B to box A, both boxes will then have the same amount of balls.

How many balls are in each box?

View Answer
Box A has 5 balls and box B has 7 balls.

How Many Fingers

Assume there are exactly 7 billion (7,000,000,000) people alive on the planet. What would be the sum if you multiplied together the number of fingers each person had on their left hand?

For this brain teaser, all thumbs count as fingers.

View Answer
The sum would be zero. All it would take is for one person to have no fingers on their left hand. Any number multiplied by zero equals zero.

Fool’s Gold

There are five identical looking bags of gold coins.  Four of the bags contain coins made of real gold and one of the bags contains coins made of fool’s gold.

All of the coins in all of the bags look identical.  They are the same size, color and shape. The only difference is their weight. Real gold coins weigh 10 grams and coins made of fool’s gold weigh 11 grams.

You have an accurate scale that you can use only one time to determine which bag contains the fool’s gold.  How do you do it?

View Answer
Take one coin from the first bag, two from the second bag, three from the third bag, four from the fourth bag, and five from the fifth bag. If the weight on the scale ends in 1 you know its the first bag, 2 the second, 3 the third, 4 fourth, and 5 the fifth bag.

Coin Confusion

You are blindfolded and wearing gloves, on the table in front of you are 100 coins.  90 of the coins are showing heads and 10 of the coins are showing tails.  You are unable distinguish which is which by touch or any other method.

You must separate the coins into two groups with an equal amount of coins in each group showing tails.  How do you accomplish this?

View Answer
You remove 10 coins and place them in a separate group.  Flip those coins over.  Now both groups will have the same number of coins showing tails.
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