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# Algebra/Algebra

Question
I have no idea how to help my son solve this problem

The letter F stands for the date that Amelia Earhart was born. Use the clues to figure out F.

1) The difference between the two digits of F is not 3.
2) F x F >= 400
3) 2 is a factor of F.
4) 3 is a factor of F.
5) 2 x F <= 60

For FxF to be at least 400, that makes F at least 20.

By (3), if 2 is a factor of F, then F is 20, 22, 24, 26, 28, or 30.

By (4), if 3 is a factor of F, the only two numbers of the last set divisible by 3 are 24 and 30.

By (5), for both cases, 2F is <= 60, for when F is 24 or F is 30, 2F is 48 or 60.

By (1), the difference between the digits for 24 is 4-2=2 and for 30 it is 3-0=3
so the 2nd choice of 30 is eliminated.

That would make the answer 24.

Just for fun, 24 is also 4 factorial (that is, 24=1*2*3*4).

Algebra

Volunteer

#### Scott A Wilson

##### Expertise

Any algebraic question you've got. That includes question that are linear, quadratic, exponential, etc.

##### Experience

I have solved story problems, linear equations, parabolic equations. I have also solved some 3rd order equations and equations with multiple variables.

Publications
Documents at Boeing in assistance on the manufacturiing floor.

Education/Credentials
MS at math OSU in mathematics at OSU, 1986. BS at OSU in mathematical sciences (math, statistics, computer science), 1984.

Awards and Honors
Both my BS and MS degrees were given with honors.

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Students in a wide variety of areas since the 80's; over 1,000 of them have been in algebra.