9.2+4+7+11+16+..." to "n" terms "=

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

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

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

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

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 ?

If S_n = (1)/(6.11) + (1)/(11.16) + (1)/(16.21) + …. to n terms then 6S_n equals

If S_(n)=(1)/(6.11)+(1)/(11.16)+(1)/(16.21)+ ….. to n terms, then 6S_(n) equals

If S_(n) = 1/(6*11)+1/(11*16)+1/(16*21)+... upto n terms , then 6S_(n) equals

lim_(n to infty) ((1)/(3.7)+(1)/(7.11) +(1)/(11.15)+. . . +(n" terms ")) =