# Math puzzle that involve thought process

1. Nov 15, 2012

### h0llow

A number of aliens, who have just dropped in from another planet, emerge from the spacecraft.

(i) There is more than one alien
(ii) each alien has the same number of fingers
(iii) each alien has at least one finger on each hand.
(iv) the total number of fingers of all the aliens is between 200 and 300.
(v) if you knew the total number of fingers of all the aliens, you would know how many aliens there are.

how many aliens are there?

2. Nov 15, 2012

### Vargo

Don't know but I'm pretty sure they landed on Yellow Pigs Day

3. Nov 15, 2012

### Norwegian

Not a bad problem! But you need to add something about one or all of the aliens having more than one hand.

4. Nov 15, 2012

### h0llow

the question doesn't mention anything about how many hands the aliens have

5. Nov 16, 2012

### AlephZero

If doesn't matter. Different aliens can have different numbers of hands, and each alien can have different numbers of fingers on each of their hands, so long as the total number of fingers per alien is the same.

(I got the answer, but I'm not spoling it for everybody else yet!)

6. Nov 16, 2012

### Norwegian

So the mentioning of hands is there only to confuse?

And are we supposed to interpret the grammar of (ii) to mean at least two fingers?

7. Nov 16, 2012

### AlephZero

In British and American english, (ii) means "each alien has $n$ fingers, where $n \ge 0$".

I think the "each hand" in (iii) implies the number of hands is $\gt 1$ and therefore $n \gt 1$.

8. Nov 16, 2012

### arildno

A prime example of a clever problem even though the solution stares you squarely in the face ..

9. Nov 18, 2012

### h0llow

thx for replies, i got the answer..quite easy when u think about it.

10. Nov 19, 2012

### daveb

Cute hint there!