The 15th term of the series `2 1/2+1 7/(13)+1 1/9+(20)/(23)+ i s` `(10)/(39)` b. `(10)/(21)` c. `(10)/(23)` d. none of these

The 7th term of the series 1,-1/2,1/4,.... is

The rth term of the series 2((1)/(2))+1((7)/(13))+1((1)/(9))+(20)/(23)+.... is

The 5th term of the series (10)/(9),(1)/(3)sqrt((20)/(3)),(2)/(3),… is

The nth term of the series 2 1/2+1 7/3+1 1/9+20/23+………. Is (A) 20/(5n+3) (B) 20/(5n-3) (C) 20(5n+3) (D) 20/(5n^2+3)

7th term of the sequence 1,3,9,23,53,115 is

The sum to n terms of the series (1)/(sqrt(7)+sqrt(10))+(1)/(sqrt(10)+sqrt(13))+(1)/(sqrt(13)+sqrt(16))+... is

The 7th term of an H.P. is (1)/(10) and 12th term is (1)/(25) Find the 20th term

If "S" is the sum of the first "10" terms of the series tan "^(-1)((1)/(3))+tan^(-1)((1)/(7))+tan^(-1)((1)/(13))+tan^(-1)((1)/(21))+.... ,then "tan(S)" is equal to:

The value of "^20 C_0+^(20)C_1+^(20)C_2+^(20)C_3+^(20)C_4+^(20)C_ 12+^(20)C_ 13+^(20)C_14+^(20)C_15 is a. 2^(19)-(( "^(20)C_10 + "^(20)C_9))/2 b. 2^(19)-((^(20)C 10+2xx^(20)C9))/2 c. 2^(19)-(^(20)C 10)/2 d. none of these