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

You are not logged in.

## #1 2013-09-03 03:51:04

mathstudent2000
Full Member

Offline

### mathcounts/amc problems

1. How many sets of 3 primes sum to 20?

2. An old book listed that 72 turkeys were bought for \$\square.\square\square each, at a total cost of \$\square 67.9\square. What was the cost of each turkey, if each \square stands for a digit that was unreadable in the old book?

Note: The \square digits are not all the same.

3. A number has three distinct digits. The sum of the digits equals the product of the digits. How many three-digit numbers satisfy this condition?

Genius is one percent inspiration and ninety-nine percent perspiration

## #2 2013-09-03 05:24:58

anonimnystefy
Real Member

Offline

### Re: mathcounts/amc problems

Hi

The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

## #3 2013-09-03 07:44:33

bobbym

Offline

### Re: mathcounts/amc problems

Hi;

2)

What does \square mean?

The only solution to the problem as you have written it is:

72 x 5.11 = 367.92

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.

## #4 2013-09-03 08:59:46

anonimnystefy
Real Member

Offline

### Re: mathcounts/amc problems

Yes, I agree. That is the only possibility.

The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

## #5 2013-09-03 10:38:24

mathstudent2000
Full Member

Offline

### Re: mathcounts/amc problems

ok

it means a box in which a unknown number is placed

Genius is one percent inspiration and ninety-nine percent perspiration

## #6 2013-09-03 10:44:27

bobbym

Offline

### Re: mathcounts/amc problems

It is the only answer, it was derived in 2 ways.

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.

## #7 2013-09-03 10:45:51

mathstudent2000
Full Member

Offline

### Re: mathcounts/amc problems

ok got it

Genius is one percent inspiration and ninety-nine percent perspiration