math
posted by Anonymous .
Find the sum of the first 33 terms of the arithmetic sequence whose first term is 3 and whose 33rd term is 253

As you (should) know,
Sn = n/2 (a1 + an)
S33 = 33/2 (a1 + a33)
= 33/2 (3  253)
= 33/2 (250)
= 33*125 = 4125
Respond to this Question
Similar Questions

arithmetic
Find the sum of the first 25 terms of an arithmetic sequence whose 7th term is −247 and whose 18th term is −49. 
Maths
1..The first 2 terms of a geometric progression are the same as the first two terms of an arithmetic progression.The first term is 12 and is greater than the second term.The sum of the first 3 terms od the arithmetic progression is … 
Algebra1
Find the sum of the first 33 terms of the arithmetic sequence whose first term is 3 and whose 33rd term is 253. 
Math
Solve for the 1st term of the arithmetic sequence whose 33rd term is 2p and whose 61st term is 26p. 
math
Find the sum of the first 60 terms of the arithmetic sequence whose first term is −15 and whose common difference is 7. 
math
in an arithmetic sequence the common difference is equal to 2.the first term is also the first term of a geometric sequence. the sum of the first 3 terms of an arithmetic sequence and the sum of the first 9 terms of an arithmetic sequence … 
math
in an arithmetic sequence whose first term is 4, the 1st, 3rd and 7th terms form consecutive terms of geometric sequence, find the sum of the first three terms of the arithmetic sequence 
Quick math help
Find the tenth term of the sequence: 6,1,8... Is it 57? 
Quick Math Help
Find the tenth term of the sequence: 6,1,8... Is it 57? 
Quick math help
Find the tenth term of the sequence: 6,1,8... Is it 57?