Problem of the Week: Round 2!

Demonknightx

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Ok, got another math problem, and since it doesnt need any graphs, i'll post my answer with it!

Mathematics Teacher Wanted

The principal of a high school needs to hire a new math teacher to replace one who is retiring. When he consults the retiring teacher concerning his replacement, the math teacher suggests placing the following advertisement to ensure that the applicant is well qualified to teach math.
Mathematics Teacher Needed. Full-time Position. If interested, please call: (ABC) DEF-GHIJ. Each digit of the telephone number is unique. A, C, G, and H are prime numbers. F, I, and J are square numbers. B, D, E, F, and G are even numbers. C is a factor of J. A + D = E + J.
What telephone number should interested applicants call?



~~ANSWER: SKIP TO FIGURE IT OUT YOURSELF!~~


The retiring math teacher of this high school is ever so clever, using a math problem to recruit a new math teacher to add to the faculty of the school. A puzzle such as this would be sure to get only the best math teacher for the job; either that or a random puzzle nerd who confused this with a new form of Sudoku puzzle. At any rate, figuring out this phone number could be as easy as guess and check in the real world. Since every number is different, one could simply make the plethora of ten-number combinations into the telephone until one reaches the number of the specific retiring math teacher, or school the teacher is needed at. Another way around this problem would be to simply call the school and ask for the position, but again, where is the fun in that? Any math teacher would find this problem a breeze! One must simply break this problem down into segments.

The first step of this seemingly complex problem would be to write down the first set of facts:

A C G H are all Prime numbers

This leaves us with few options, as a telephone only reaches up to the number 9. Therefore, A C G H à 1, 2, 3, 5, or 7 in any order at this point
Now for the next set,

F I J are all square numbers

Again, this leaves us with few options: F I J à 1, 4, 9

Moving right along with the problem:

B D E F G are all even numbers

This part is cake compared to the other parts, right? Well, aside from the tricky part which is 0 being an even number, which many overlook: à0, 2, 4, 6, 8

For the next step, there are many options, where C is a factor of J, but for the sake of saving space, and saving time, and saving trees, ect, we’ll list only the correct one

C = J à 3 = 9

And finally, the last step is a simple equation of A+D = E + J (we already know what J is from the last step, so A+D = E+9 for sure)

So now that everything is documented and accounted for, the problem solving factor that would make any math teacher great comes into play.
For sure, we already know that C = 3 and that J = 9, so those numbers can get crossed off the list already à (AB3) DEF-GHI9 and, in turn, cross off C and J for any number possibilities above.

A: The option for A begins at the first part of the problem, so we know that A is a prime number, and it appears in the formula at the last part of the problem. We also know that it is in fact not an even number, nor a square number; leaving the only options being 5 or 7

B: only appears as being an even number, so it is not a square, prime, or a factoring option. It is also not mentioned in the addition formula at the end. One can assume that with these facts (not prime, not used in addition, ect) that it has no value at all, hence B being 0

C: We know this is 3 already, as stated above

D: All we know of D is the fact it is an even number, and is also in the formula at the end. Leaving only the options of, 4, 6, or 8 since 0 has been taken already

E: Is also like D, leaving 6 or 8.

F: This will be the last to be figured out, as it is not in the formula, and all we know is that it is even.

G: Is a prime number, but is also even? 2 is the only option for this, which also removes 2 from the possibilities of the above letters.

H: Is prime, and not even, leaving 5 and 7 as the only possibilities

I: since 9 is taken already, and I is not an even number, this leaves I as being the #1

J : is 9.


The most important part of figuring this problem out, is the formula at the end. Which as you might recall as A+D = E + 9 Finding E would be the best thing to do at this point, as the options are only 6 and 8. Nine plus eight would equal 17. However using the 2 highest digits possible would mean that the other 2, A and D, would in no way equal 17, which leaves E = 6 (and 6+9 = 15)

So now half of the formula is complete, and only A and D is left. But now its easy. They need to equal 15, and the only way to do that is to add 7 and 8. Now too discern which is which. One might recall, though, that A is a prime number; and the only options for that would be 7. So in conclusion to this segment of the story:

A = 7 D = 8 E = 6 J = 9

In addition to what we already know:

C = 3 B = 0 G = 2 I = 1

So the last two possibilities are 4 and 5, for F and H. However the only clue for F was it being even. So, the simple solution is that:

F = 4 H = 5

Put it all together, and the super secret phone number is:

(703) 864-2519

The lucky math teacher to figure this one out is sure to have a successful career at this high school, making a 6-digit income, driving a sports car, and live in a three-story beach house overlooking the beautiful Pacific Ocean. Because, as we all know, math teachers get paid the best salaries and deserve the best accommodations. Unfortunately, however, the phone number is in no way related to a high school, nor knows anything about math teachers or job opportunities. I tried several times to get a comment from the holder of this lucky number, wondering why he would play such a joke on prospective teachers. He promptly hung up the phone. Both times I tried calling.

Some people are just so rude.















~~ END ANSWER ~~


if you attempt it, good luck!
 
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