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#1 2013-09-02 05:51:04

mathstudent2000
Member
Registered: 2013-07-26
Posts: 79

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

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#2 2013-09-02 07:24:58

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,657

Re: mathcounts/amc problems

Hi



“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#3 2013-09-02 09:44:33

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 90,454

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 agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.

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#4 2013-09-02 10:59:46

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,657

Re: mathcounts/amc problems

Yes, I agree. That is the only possibility.


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#5 2013-09-02 12:38:24

mathstudent2000
Member
Registered: 2013-07-26
Posts: 79

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

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#6 2013-09-02 12:44:27

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 90,454

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 agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.

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#7 2013-09-02 12:45:51

mathstudent2000
Member
Registered: 2013-07-26
Posts: 79

Re: mathcounts/amc problems

ok got it


Genius is one percent inspiration and ninety-nine percent perspiration

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