Five Three Two

What is the answer to the last equation?

5 3 2 = 151012
9 2 4 = 183662
8 6 3 = 482466
5 4 5 = 202504
7 2 5 = ?

10000 × (x × y) + 100 × (x × z) + transpose_digits(x × y + y × z)

transpose_digits() just swaps the digits

Posted in Brain Teasers

ROFORKAD

What does this rebus represent?

ROFORKAD

A fork in the road.

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Which Switch?

You are standing outside a closed door. On the other side of the door is a room that has three light bulbs in it. The room is completely sealed off from the outside. It has no windows and nothing can get in or out except through the door. On the outside of the room there are three light switches that control each of the respective light bulbs on the other side of the door.

Your assignment is to determine which light switch controls which light bulb. You are allowed to enter the room only once, and once you come out, you must be able to state with 100% certainty which light switch controls which light bulb.

Turn one light switch on, wait a few minutes, then turn it off and turn another light switch on. Go into the room and feel the light bulbs. The one that’s still warm is connected to the switch that you first turned on, the one that is on was the second switch you turned on, and the last bulb is controlled by the switch that you didn’t touch.

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A Smiling Guard

Two guards were on duty outside a barracks. One faced up the road to watch for anyone approaching from the North. The other looked down the road to see if anyone approached from the South. Suddenly one of them said to the other, “Why are you smiling?”

How did he know his companion was smiling?

They were facing each other. As to why his companion was smiling, the world may never know.

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Which Door First?

While driving his car a man slams on the brakes when he sees, in the middle of the street, a diamond studded door, a gold door and a silver door. Which door does he open first?

His car door

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Falls But Never Breaks

What falls but never breaks and breaks but never falls?

Night and day.

Posted in Riddles

Tabitha and Ronan’s Age

Tabitha is 13 years old. Her father Ronan is 40 years old. How many years ago was Ronan four times as old as Tabitha?

Four years ago, when Tabitha was 9 and Ronan was 36 (9 × 4 = 36)

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Rope Around The Earth

If a piece of rope was tightly wrapped around the earth and you added 3 feet to its length, how high could you uniformly raise it from the earth’s surface?

Just short of 6 inches.

Thanks to Nigel Coldwell for this one.

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What Goes In the Water Red?

What goes in the water red
And comes out black?

Iron

Posted in Riddles

A Person, Place and Thing

Fill in the blanks to make three common, English words (no plurals). The answers are a person, a place and a thing, in that order.

1. _ _ L F B A _ _
2. _ _ _ C K Y A _ _
3. _ _ O D P E _ _ _ _

1. HALFBACK
2. BRICKYARD or STOCKYARD
3. WOODPECKER

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