" 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,….

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

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

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?

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

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?

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?

In a GP, the sum of the first three terms is 5, and the sum of the next three terms is 625. Find the sum of the first n terms of the GP.