Sum of `(3xx8)+(6xx11)+(9xx14)+.......`upto 'n' terms is:
a) `n(n+1)(3n+1)`
b) `n(n+1)(3n+9)`
c) `n(n+1)(3n+9)/3`
d) `n(n+1)^2`

Sum the series 3. 8+6. 11+9. 14+............... to n terms.

The sum of the series 2/3+8/9+(26)/(27)+(80)/(81)+ to n terms is (a) n-1/2(3^(-n)-1) (b) n-1/2(1-3^(-n)) (c) n+1/2(3^n-1) (d) n-1/2(3^n-1)

Prove 1.4.7+2.5.8+3.6.9+....... upto n terms =(n)/(4)(n+1)(n+6)(n+7)

If the sums of n terms of two arithmetic progressions are in the ratio (3n+5)/(5n+7) , then their n t h terms are in the ratio (3n-1)/(5n-1) (b) (3n+1)/(5n+1) (c) (5n+1)/(3n+1) (d) (5n-1)/(3n-1)

If 1+(1+2)/2+(1+2+3)/3+ddotto\ n terms is Sdot Then, S is equal to a. (n(n+3))/4 b. (n(n+2))/4 c. (n(n+1)(n+2))/6 d. n^2

The sum to n terms of the series 1+ 5 ((4n +1)/(4n - 3)) + 9 ((4n +1) /( 4n -3)) ^(2) + 13 ((4n +1)/( 4n -3)) ^(3) + ((4n + 1 )/( 4n -3)) ^(2)+ ……. is .

Sum of n terms of series 12+16+24+40+.... (A) 2(2^n -1)+8n (B) 2(2^n-1)+6n (C) 3(2^n-1)+8n (D) 4(2^n-1)+8n

If f(r)=1+1/2+1/3+1/ra n df(0)=0,t h e nsum_(r=1)^n(2r+1)f(r) is equal to (a) nf(n+1)-((n^2-3n+2))/2 (b) (n+1)^2f(n)-((n^2-3n+2))/2 (c) (n+1)^2f(n+1)-((n^2+3n+2))/2 (d) (n+1)^f(n+1)-((n^2-3n+2))/2

Sum of n terms of the series (2n-1)+2(2n-3)+3(2n-5)+... is

Find the sum of series upto n terms ((2n+1)/(2n-1))+3((2n+1)/(2n-1))^2+5((2n+1)/(2n-1))^3+...