" 6."2+4+7+11+16+.........." to "n" terms "=

1/2+3/4+7/8+15/16+..... t o n terms =

Find the sum of indicated number of terms of the following arithmetic progression : 16, 11, 6,..........., n terms, 23 terms.

2+ 4+ 7 + 11 + 16 + ….. upto n terms is equal to

3.6+4.7+5.8+.....+(n-2) terms =

If S_1 = 3, 7, 11 15, … upto 125 terms and S_2 = 4, 7, 10, 13, 16, … upto 125 terms the how many terms are there in S_1 that are there in S_2 ?

2.4 + 4.7 + 6.10+ …. upto (n-1) terms=

Prove the following by the method of induction for all n in N : 3 + 7+ 11 +.. to n terms = n(2n + 1).

Find 1.4.7 + 3.6.9 + 5.8.11 + 7.10.13 …. Upto 'n' term.

If (5 + 9 + 13 + .... rarr nterms) / (7 + 9 + 11 + ... rarr (n + 1) terms) = (17) / (16), then n =