Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

Pages: **1**

**whatthe****Member**- Registered: 2012-05-27
- Posts: 6

Ive been asked to solve the following:

1,4,16,25,....,....,....any tips on the next 3 numbers.

Ive come up with 49,64,100

I could understand if there was a 9 between the 1 & 4 but it wasnt in the question.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 84,512

Hi;

Welcome to the forum. I am getting that too.

**In mathematics, you don't understand things. You just get used to them.I have the result, but I do not yet know how to get it.All physicists, and a good many quite respectable mathematicians are contemptuous about proof.**

Offline

**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 6,308

hi whatthe

Welcome to the fourm!

Me too. You could probably make up a rule to allow for that like:

The square numbers leaving out every third square, which seems to be your idea, but four instances are not enough to establish that rule properly.

The square numbers leaving out any square with a 9 in it would give 1,4,16,25,36,64,81, ...

I wonder if there's any clue in the source?

Where did you get it from?

Bob

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

Offline

**whatthe****Member**- Registered: 2012-05-27
- Posts: 6

An aptitude test for yr 10 students, got it from a TAFE Teacher.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 84,512

Hi whatthe;

Those aptitude tests where people guess a pattern are mathematically incorrect in the sense that there are an infinite number of patterns ( equations ) from the same set of data. Each one just as valid as any other.

**In mathematics, you don't understand things. You just get used to them.I have the result, but I do not yet know how to get it.All physicists, and a good many quite respectable mathematicians are contemptuous about proof.**

Offline

**noelevans****Member**- Registered: 2012-07-20
- Posts: 236

Amen to that bobbym!

I hate such questions. It just shows the ignorance of the test writers. The sequence could have

been 1,4,16,25,1,4,16,25,1,4,16,25... or 1,4,16,25,pi,1,4,16,25,pi... or any repeating sequence

that begins with 1,4,16,25 among other possibilities like 1,4,16,25,28,30,39,... where one keeps

adding 3 then 12 then 9 repeatedly.

Also those tests that have 3 (usually) pictures and the test taker is supposed to figure out the fouth

picture (from a list of 4 or more given pictures) are faulty. Those that don't think the same way

that the test maker does have their answers counted wrong although they may have just as valid

a reason for their choice.

Some of the questions on those tests sometimes show a lack of understanding of the test taker's

creativity and intelligence.

I saw a test once that was testing quality control. Out of 100 questions 10 of them were messed

up one way or another. One of the questions was:

A stock was purchased for $100. At the end of the 1st month it had lost 50% of its value. In

the next month it gained 50% of the value it had at the end of the 1st month. How much was

the stock worth at the end of the 2nd month?

Choices

a) $100

b) $75

c) $50

d) It's hard to understand the stock market.

e) $200

Their "correct answer" was b AND d.

Go figure! How can one pass a test with such questions?

It's easy to understand the stock market: people buy and sell stocks.

PREDICTING what the stock market is another matter.

Writing "pretty" math (two dimensional) is easier to read and grasp than LaTex (one dimensional).

LaTex is like painting on many strips of paper and then stacking them to see what picture they make.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 84,512

Those that don't think the same way

that the test maker does have their answers counted wrong

Yep!

Find the next term 1, 2, 4,...

Answer 8, brilliant! The interrogator is happy. But what about the simpler answer of 7?

**In mathematics, you don't understand things. You just get used to them.I have the result, but I do not yet know how to get it.All physicists, and a good many quite respectable mathematicians are contemptuous about proof.**

Offline

**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 6,308

Bob

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

Offline

**noelevans****Member**- Registered: 2012-07-20
- Posts: 236

Or maybe the next for 1,2,4 considering it as a list of consecutive positive integers whose spelling is less than five letters long:

1, 2, 4, 5, 6, 9, 10 --- a FINITE sequence.

Writing "pretty" math (two dimensional) is easier to read and grasp than LaTex (one dimensional).

LaTex is like painting on many strips of paper and then stacking them to see what picture they make.

Offline

**Calligar****Member**- Registered: 2011-09-24
- Posts: 234

Hi whatthe!

Welcome to the forum!

Life isnt a simple Math: there are always other variables. -[unknown]

But Nature flies from the infinite, for the infinite is unending or imperfect, and Nature ever seeks an end. -Aristotle

Offline

Pages: **1**