What is the First Number of the Sequence?

If a number in a numeric sequence is 17 and the second number is 3, what is the first number?

I hesitated to add this because it’s poorly worded, ambiguous and the answer could be almost anything. I prefer teasers with a single answer, but there you go.

If you came up with a different answer and can explain how you did it, don’t think you’re wrong. It’s probably just as valid. Feel free to share yours in the comments.

My answer for the first number is 2.

Here’s how I got it.

The generic rule for a number in the sequence is: 2^(n – 1) + 1, where n is the position in the sequence.

Note: The teaser doesn’t specify the position of 17. In this case, it’s fifth.

Position 1: (so n = 1) is 2^(1 – 1) + 1 = 2

Position 2: 2^(2 – 1) + 1 = 3

Position 3: 2^(3 – 1) + 1 = 5

Position 4: 2^(4 – 1) + 1 = 9

Position 5: 2^(5 – 1) + 1 = 17

For the curious, the next 5 numbers of the sequence would be:

Position 6: 2^(6 – 1) + 1 = 33

Position 7: 2^(7 – 1) + 1 = 65

Position 8: 2^(8 – 1) + 1 = 129

Position 9: 2^(9 – 1) + 1 = 257

Position 10: 2^(10 – 1) + 1 = 513

Posted in Brain Teasers

I Sleep By Day

I sleep by day, I fly by night. I have no feathers to aid my flight. What am I?

A bat.

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Pitching On The Merry-Go-Round

Everly and I were playing on the merry-go-round at the local park. It was very large and we stood on opposite sides. As we spun the merry-go-round counter-clockwise, I threw a ball to Everly. Did the ball go to Everly, to the right or left of them?

Since the merry-go-round had moved while the ball was traveling to Everly the ball went to the right of them.

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Can’t Be Touched, Can Be Felt

It can’t be touched, but can be felt.
It can’t be opened, but can be gone into.
Those who seek it always find it under something,
yet it moves from place to place.

Shade. You can’t touch shade, but you can feel its coolness. You can’t open shade but you can go into it. If you’re looking for shade it always has to be underneath something to block the light and shade moves as the light does.

Written by Sef Daystrom

Posted in Riddles

Brothers And Sisters Of Leopold

If Leopold had one more sister he would have twice as many sisters as brothers.
If he had one more brother he would have the same number of each.

How many brothers and sisters does Leopold have?

Three sisters and two brothers.

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Long or Short, Grown or Bought

I can be long or short. I can be grown or bought. I can be painted or left bare. My tip can be round or square. What am I?

Fingernails.

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The Man in the Picture

A man is looking at a picture on the wall and says, “Brothers and sisters I have none, but this man’s father is my father’s son.”

What is their relationship?

The man in the picture is the onlooker’s son. Since he doesn’t have any brothers or sisters, the statement my father’s son can only be himself. A shortened version would be this man’s father is me, making him the father of the man in the picture.

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Liquid In Nature

I am liquid in nature,
But don’t bend me to far,
For then I may break
And give you a scar.

What am I?

Glass. Technically, glass is an amorphous solid, but that doesn’t have the same ring to it.

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Who May Enter?

A green glass door admits only certain objects. Apples and balls are allowed, but pears and bats aren’t. What determines whether an item can enter?

All words with a repeated letter are allowed. Green glass door, apple and ball.

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The Color of Clouds

First, think of the color of clouds. Next think of the color of snow. Last, think of the color of the moon. Now, what do cows drink?

Water. If the teaser worked, you guessed milk.

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