math cat ?

[gmatxyz]

If ¡n! = (n!) 2, then ¡17! - ¡16! =




¡1!


(¡16!)(¡4!)(2)


(¡16!)(12)(2)


172



(¡16!)(122)(2)




is the answer to this cat question wrong? shouldn't there be 2 16!s in the answer?

[RonPurewal]

something is wrong with your transcription of the problem.

if you tried to copy and paste it... well... there's your issue. you can't do that—if you copy and paste, then the exponents won't be exponents anymore. (ALWAYS PROOFREAD.)

presumably the correct answer is supposed to be (e), and the middle term is supposed to be 12^2?
(also, please read the forum rules before posting... among other things, you ALWAYS must post the correct answer along with the problem.)

[RonPurewal]

in any case—i think i see what the problem is.

there is only one "¡16!" in the problem. that is exactly what should be there.

if the thing in the choices were just "16!" (NOT "¡16!") then there would have to be two of those...
...but it isn't.

¡16! is 16! times 16!, so, there you go.

[RonPurewal]

in any case, this thread is now locked, because at least 2 forum rules are not followed here (the problem is transcribed incorrectly, and the correct answer is missing).

if you have further questions, please post the problem correctly, with the correct answer, in another thread. thanks.