" 9.What is the sum of first "n" terms of the "APa,3a,5a,

What is the sum of first n terms of the AP a, 3a, 5a,….

Sum of the first 15 terms of an arithmetic sequençe is 495 and sum of first 25 terms is 1325 . i) What is the common difference of this sequence? ii) What is the first term? iii) What is the sum of first n terms of this sequence?

If the sum of the first 2n terms of the AP 2,5,8.....is equal to the sum of the first n terms of the AP 57,59,61, ....then n equals

If the sum of the first 2n terms of the AP 2, 5, 8 ....is equal to the sum of first n terms of the AP 57, 59, 61, ..., then what is the value of n?

The sum of first n terms of an arithmetic sequence is n^2+2n What is the sum of first 20 terms of this sequence?

What is the sum of the first n term of the arithmetic sequence 1,3,5,7......?

Find the sum of first 24 terms of the A.P.a_(1),a_(2),a_(3),..., if it is know that a_(1)+a_(5)+a_(10)+a_(15)+a_(20)+a_(24)=225

Find the sum of first 24 terms of the A.P.a-1,a_(2),a_(3),... if it is inown that a_(1)+a_(5)+a_(10)+a_(15)+a_(20)+a_(24)=225

(i) Find the sum of first 24 terms of the A.P.a_(1),a_(2),a_(3),...... if it is know that a_(1)+a_(5)+a_(10)+a_(15)+a_(20)+a_(24)=225