Math Is Fun Forum

Mariner

Member

Registered: 2010-06-16

Posts: 35

Sequencing

Hi, I was wondering if I could get your help on some particular number sequence questions and the tricks behind them.

Here are a few.

10, ?, 41, 17, 52, 09
15, ?, 70, 18, 52, 00

Thanks,

Bob

Administrator

Registered: 2010-06-20

Posts: 10,621

Re: Sequencing

Hi Mariner,

I looked at these yesterday and hoped someone else would pick up your problem.  But alas, no one has.

The trouble is: there's no obvious pattern so no wonder you are stuck.  If you write down any five numbers at random, it is possible to fit a formula to them but that's not what you want I suspect.

These go up and down so that counts out 'plus x', 'subtract x' , 'multiply by x' and 'divide by x'.  So I thought maybe there are two interlocked sequences, but I haven't got enough numbers for that, so I have to admit defeat at the moment.  Sorry

But this post will  refresh the thread with New Post so maybe someone else will spot something.

Bob

Last edited by Bob (2010-12-20 00:01:22)

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: Sequencing

Why are the last numbers written 09 and 00 rather than 9 and 0? Is that supposed to be a clue?

Last edited by JaneFairfax (2010-12-21 07:42:03)

stapel

Member

Registered: 2006-07-22

Posts: 15

Re: Sequencing

Hi, I was wondering if I could get your help on some particular number sequence questions and the tricks behind them.

Here are a few.

10, ?, 41, 17, 52, 09
15, ?, 70, 18, 52, 00

Try breaking up the numbers into sets of three digits. Remove the commas and try to find a pattern in:

. . . . .10_, _41, 175, 209

. . . . .15_, _70, 185, 200

There is no real "trick" to this. I just happened to think of it and it just happened to work.

soroban

Member

Registered: 2007-03-09

Posts: 452

Re: Sequencing

.

. .

.

Last edited by soroban (2010-12-22 11:51:16)

Monox D. I-Fly

Member

From: Indonesia

Registered: 2015-12-02

Posts: 2,000

Re: Sequencing

.

Because it contains "math"?

I knew it.

Last edited by Monox D. I-Fly (2017-11-07 18:52:04)

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Actually I never watch Star Wars and not interested in it anyway, but I choose a Yoda card as my avatar in honor of our great friend bobbym who has passed away.
May his adventurous soul rest in peace at heaven.