Sunday, November 27, 2005

8th Grade Math




You Passed 8th Grade Math



Congratulations, you got 10/10 correct!

12 comments:

DaPi said...

# -7 is

* Irrational
* An integer
* A whole number
* A prime number


THAT'S A STRANGE QUESTION - 3 answers are correct!

Anonymous said...

So, is -7 an irrational or a prime? Can't figure that one out.

Jeff Hunter said...

THAT'S A STRANGE QUESTION - 3 answers are correct!
Well, no.

It's not a prime number because prime numbers are >= 2.

Whole number is a little more tricky. Some definitions of "whole number" define them as integers. On the other hand, some define them as "positive integers".

I'll admit, I chose integer as a best guess.

Pete_S said...

How old is 8th grade?



(btw I scored 10/10 but I think I may be too old!)

Jeff Hunter said...

How old is 8th grade?
13-14ish...

gandolf989 said...

Apparently I would have gotten a B. I guessed that -7 was irrational. How can you have -7 apples?

Joel Garry said...
This comment has been removed by a blog administrator.
Bob B said...

-7 is an integer.

It is not irrational because it can be expressed as a ratio (e.g. -7/1). Rational and irrational numbers are distinct sets.

It is not a whole number because it is negative. Whole numbers are non-negative (they might be strictly positive, I'm a little fuzzy on that detail)

Is not a prime number. Prime numbers are a subset of the whole numbers. Since -7 is not a whole number, it is not a prime number.

Noons said...

Duh? Is there ANY integer number that cannot be expressed as a n/1 ratio?

Me theenks it's just an integer:
whole numbers must be positive. Primes must be positive. Irrational it ain't as it is not a ratio to start with.

Anonymous said...

strange

primes

You owe me seven apples, gandalf

DaPi said...

I'd say:

It's clearly rational - or would someone argue that numerators and denominators of rationals must be >=0 ?

It's a whole number - it has no fractional part.

It's an integer - for me: integer = whole number

It's a prime: its factors are 1 and -7 (if anyone argues against, saying that -1 and 7 are also factors, then 7 also fails to be prime with factors 1, 7, -1 and -7)

It's NOT a "natural number", which are the members of the set 1,2,3,4 . . . .

Very roughly, I'd consider -7 to have all the properties of 7, except that of being positive.
Any professional mathematician out there to put me straight?

Roger Snowden said...

Well, that was fun.

Nuno-

It's only irrational if you use it to calculate a baseline. :-)