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

The White Liquid

She awakes. I touch her and she moves her legs. We are both nervous but I continue. Finally the white liquid comes.

What happened?

Milking a cow.

Posted in Riddles
Tagged with

Three Children’s Names

Tom’s mother has three children. One is named April, one is named May. What is the third one named?

Tom

Posted in Brain Teasers

Jim and Wanda’s Apples

Jim and Wanda both have some apples. If Jim gives Wanda an apple, they will both have the same number of apples. However, if Wanda gives Jim an apple, Jim will have twice as many as Wanda. How many apples do Jim and Wanda each have?

Jim has 7 apples and Wanda has 5 apples.

Posted in Brain Teasers

Priscilla and Bruce Exchanging Money

Priscilla gave her brother Bruce as much money as Bruce started with. Bruce gave Priscilla as much money as Priscilla had left. Priscilla then gave Bruce as much as Bruce had left, which left Priscilla broke. Bruce had $80.00.

How much money did Priscilla and Bruce start with?

Priscilla: $50
Bruce: $30

Step 1
Priscilla gives Bruce $30
Priscilla: $20
Bruce: $60

Step 2
Bruce gives Priscilla $20
Priscilla: $40
Bruce: $40

Step 3
Priscilla gives Bruce $40
Priscilla: $0
Bruce: $80

Posted in Brain Teasers

Four Times Every Week

What happens four times in every week, twice in every month and once in a year?

The letter ‘e’. There are four ‘e’s in ‘every week’, two ‘e’s in ‘every month’ and one ‘e’ in ‘year’.

Posted in Riddles

Walk On the Living

Walk on the living, they don’t even mumble,
Walk on the dead, they mutter and grumble.

What are they?

Leaves. They’re soft and silent when they’re alive but crunchy when dead.

Posted in Riddles
Tagged with

The 500 Mile Race

Mike, Jimmy, Nader, Kevin, and Larry were the top five finishers in the regional 500-mile race. They drove yellow, orange, green, red and blue cars but not necessarily in that order.

Neither Kevin nor Larry drove the green car.
Kevin finished faster than Mike and Larry.
The blue car finished earlier than Larry’s and Nader’s car.
The yellow car finished faster than the green car and the orange car.
Mike’s and Larry’s car finished ahead of the orange car.
Jimmy’s car finished before the blue and the yellow car.

Who drove what color car and what place did each driver finish?

1st – Jimmy, red car
2nd – Kevin, blue car
3rd – Larry, yellow car
4th – Mike, green car
5th – Nader, orange car

Posted in Brain Teasers

Don’t Speak But No Word I Cannot Make

I don’t speak but there is no word I cannot make. What am I?

The alphabet.

Posted in Riddles

Famous for the Friendly Folk

I have palms but not on hands,
I offer foods from distant lands,
When at my peak you’ll see me smoke,
I’m famous for my friendly folk,
My flowers grow and yet they lay,
There’s fire where a man will play,
I’m sure you know we’re family,
You’re welcome to come stay with me.

What am I?

Hawaii.

Posted in Riddles