Raymond B. answered • 03/13/23
Math, microeconomics or criminal justice
this answer is under construction.
check back later for more details,
problem is though, once I leave this problem, it's nearly impossible to find it again,
and the computer seems to have a mind of its own, on when the screen disappears
so what you see may be all there is, but for what it's worth here it is
try this sequence, 31,32, 69, 88
31+69 = 100
32+88 = 120
n=4
seems to almost work, but 31+38 =69 not an=a4=88
another stab at it:
138, -38
how about this sequence: 31,120, 69?
it works except n=3 when you seem to want an even number of digits
back to the drawing board
how about
an arithmetic sequence, then
an =a1 +38
odd terms sum to 100
even terms sum to 120
find n
17 is close
s17= 17/2)(-10+22)= 102
s17=(17/2)(-9+23)=119
2 points in horse shoes
a kill or 2 in hand grenades
you did say "any help" is appreciated
this falls under the "any" part
whatever number n you come up with it should satisfy
sn = (n/2)(a1 + an-1) = 100
and
sn (n/2)(a2 + an) = 120
or use those equations to work backward, reverse engineer, to find n
plug in an = a1 +38
odds are a possible typo in the problem, somewhere. Just change 100 to 102, 120 to 119, and the even digits to odd, then 17 is the soluition, for an arithmetic sequence.
might try a geometric sequence, or other types of sequences. there could be an infinite number of solutions
it's starting to be understandable why no one attempted to answer this quetstion
there's a formula for the sum of a geometric sequence, finite and infinite
there's still a lingering suspicion, there is no possible solution.
it's an intriguing problem though, either way
