In the Challenge Archive, 2002 JUL-SEP, September 30th "Neighborly Numbers" Given that n is an integer, is n "” 1 divisible by 3? (1) n² + n, is not divisible by 3 (2) 3n+5 ≥ k+8, where k is a positive multiple of 3 I know that using Statement (1) (n-1)n(n+1) is three consecutive intege...

Sorry if you look at the answer to the question in the Challenge Problem Archives it says n - 1 is divisible by 3... I'm a little confused on your plugging in numbers theory, Statement (1) says n² + n is not divisible by 3... therefore you cannot plug in numbers like 6 & -6... if you do plug in...

Hi... i'm not gonna lie this just drove me crazy too... I thought because l=2πr there was a way to break it down there... it turns out the 15lr-r is actually 15/r-r... the fraction/division sign just looks exactly like the 'l' they use in the problem... so (15/r-r)*r = 15-r² i'm sure you get it fr...

I would approach this as a diagram... just draw a circle with the center at 0,0... with a radius of 1 the circle will touch (0,1) (1,0) (0,-1) & (-1,0) Statement (1) tells you that line K (and i'm pretty sure that yes you imagine it's infinite because it would be called line segment k something ...

if n is 1 than n-1 is 0... not divisible by 3??? that's what i'm confused on... 1 satisfies statement 1 but n-1 would be zero and isn't divisible by 3...


and the answer given is A (and says n-1 is divisible by 3)

thank you for trying to help

is there a way to get an instructor to look at this???