Homework Statement
In an arithmetic progression, the sum of the first 10 terms is the same as the sum of the next 5 terms. Given that the first term is 12, find the sum of the first 15 terms.
2.
The only one I could think of is
S= n/2 (2a+(n-1)d)
3.
I've tried solving it, but failed. I...
Howdy ho. No reason for a welcome around here, it's not about me it's about the Mathematical Anti-Telharsic Harfatum Septomin, eh!? (I hope at least one of you are familiar with that guy) Nonetheless, I've become obsessed with the transcendental property, and thusly therein my familiarization...
I have a solution to a problem which I am not certain that is complete. (It's a putnam problem so I can't believe I solved it) Would you mind to take a look at it?
The problem stated:
"Let A be any set of 20 distinct integers chosen from the arithmetic progression 1,4,7,...,100. Prove that...
MATHWORLD: "Erdos offered a prize for a proof of the proposition that 'If the sum of reciprocals of a set of integers diverges, then that set contains arbitrarily long arithmetic progressions.' This conjecture is still open (unsolved), even for 3-term arithmetic progressions. "
What's an...
The first term of an arithmetic progression is (1-x)^2 and the second term is 1+x^2 .If the sumj of the first ten terms is 310 , find the possible values of x.
I have my A/S maths exam next month, but i am still having trouble with arithmetic progression. The above question is causing me some...
in an arithmetic sequence there is an even number of term's
the sum of terms in the odd places is 440 and the sum of terms in the even places is 520, the last term is bigger than the first term by 156
find how many term's the arithmetic sequence has.