" If "1-(1)/(3)+(1)/(5)-(1)/(7)+(1)/(9)-(1)/(11)+.....=(pi)/(4)" ,then value of "(1)/(1times3)+(1)/(5times7)+(1)/(9times11)+...." is "

If 1-(1)/(3)+(1)/(5)-(1)/(7)+(1)/(9)-(1)/(11)+...=(pi)/(4), then value of (1)/(1xx3)+(1)/(5xx7)+(1)/(9xx11)+... is pi/8bpi/6c. pi/4d. pi/36

(1)/(5)times(11)/(13)+7(4)/(5)times(1)/(13)=

[(1)/(5)times(1)/(4)],[ (1)/(5)times(7)/(2)]

(1)/(1times3)+(1)/(3times5)+(1)/(5times7)+(1)/(7times9)+(1)/(9times11)+(1)/(11times13)

7.The value of (1)/(1.2.3.4)+(1)/(2.3.4.5)+......+(1)/(9.10.11.12) is

Simplify -(2)/(3)times5(1)/(2)times2times7(5)/(6)times(9)/(11)

(5)/(6) -: (6)/(7) xx ? - (8)/(9) -: 1 (2)/(5) -: (3)/(4) xx 3 (1)/(3) = 2(7)/(9)

If 1-1/3+1/5-1/7+1/9-1/(11)+=pi/4 , then value of 1/(1xx3)+1/(5xx7)+1/(9xx11)+ is pi//8 b. pi//6 c. pi//4 d. pi//36

If 1-1/3+1/5-1/7+1/9-1/(11)+=pi/4 , then value of 1/(1xx3)+1/(5xx7)+1/(9xx11)+ is pi//8 b. pi//6 c. pi//4 d. pi//36