Maths-
General
Easy

Question

The sum to 50 terms of the series fraction numerator 3 over denominator 1 to the power of 2 end exponent end fraction plus fraction numerator 5 over denominator 1 to the power of 2 end exponent plus 2 to the power of 2 end exponent end fraction plus fraction numerator 7 over denominator 1 to the power of 2 end exponent plus 2 to the power of 2 end exponent plus 3 to the power of 2 end exponent end fraction plus horizontal ellipsis is

  1. fraction numerator 100 over denominator 17 end fraction   
  2. fraction numerator 150 over denominator 17 end fraction   
  3. fraction numerator 200 over denominator 51 end fraction   
  4. fraction numerator 50 over denominator 17 end fraction  

The correct answer is: fraction numerator 100 over denominator 17 end fraction


    Let T subscript r end subscript be the r to the power of t h end exponent term of the given series. Then,
    T subscript r end subscript equals fraction numerator 2 r plus 1 over denominator 1 to the power of 2 end exponent plus 2 to the power of 2 end exponent plus horizontal ellipsis plus r to the power of 2 end exponent end fraction
    equals fraction numerator 6 left parenthesis 2 r plus 1 right parenthesis over denominator open parentheses r close parentheses open parentheses r plus 1 close parentheses left parenthesis 2 r plus 1 right parenthesis end fraction
    equals 6 open parentheses fraction numerator 1 over denominator r end fraction minus fraction numerator 1 over denominator r plus 1 end fraction close parentheses
    So, sum is given by
    not stretchy sum from r equals 1 to 50 of T subscript r end subscript equals 6 not stretchy sum from r equals 1 to 50 of open parentheses fraction numerator 1 over denominator r end fraction minus fraction numerator 1 over denominator r plus 1 end fraction close parentheses
    equals 6 open square brackets open parentheses 1 minus fraction numerator 1 over denominator 2 end fraction close parentheses plus open parentheses fraction numerator 1 over denominator 2 end fraction minus fraction numerator 1 over denominator 3 end fraction close parentheses plus open parentheses fraction numerator 1 over denominator 3 end fraction minus fraction numerator 1 over denominator 4 end fraction close parentheses plus horizontal ellipsis plus open parentheses fraction numerator 1 over denominator 50 end fraction minus fraction numerator 1 over denominator 51 end fraction close parentheses close square brackets
    equals 6 open square brackets 1 minus fraction numerator 1 over denominator 51 end fraction close square brackets
    equals fraction numerator 100 over denominator 17 end fraction

    Related Questions to study

    General
    Maths-

    If a comma blank x and b are in A.P., a comma blank y comma and b are in G.P. and a comma blank z comma blank b are in H.P. such that x equals 9 z and a greater than 0 comma blank b greater than 0, then

    If a comma blank x and b are in A.P., a comma blank y comma and b are in G.P. and a comma blank z comma blank b are in H.P. such that x equals 9 z and a greater than 0 comma blank b greater than 0, then

    Maths-General
    General
    Maths-

    Let a subscript 1 end subscript comma a subscript 2 end subscript comma horizontal ellipsis comma a subscript 10 end subscript be in A.P. and h subscript 1 end subscript comma h subscript 2 end subscript comma horizontal ellipsis comma h subscript 10 end subscript be in H.P. If a subscript 1 end subscript equals h subscript 1 end subscript equals 2 and a subscript 10 end subscript equals h subscript 10 end subscript equals 3, then a subscript 4 end subscript h subscript 7 end subscript is

    Let a subscript 1 end subscript comma a subscript 2 end subscript comma horizontal ellipsis comma a subscript 10 end subscript be in A.P. and h subscript 1 end subscript comma h subscript 2 end subscript comma horizontal ellipsis comma h subscript 10 end subscript be in H.P. If a subscript 1 end subscript equals h subscript 1 end subscript equals 2 and a subscript 10 end subscript equals h subscript 10 end subscript equals 3, then a subscript 4 end subscript h subscript 7 end subscript is

    Maths-General
    General
    Maths-

    If x comma blank y comma blank z are real and 4 x to the power of 2 end exponent plus 9 y to the power of 2 end exponent plus 16 z to the power of 2 end exponent minus 6 x y minus 12 y z minus 8 z x equals 0, then x comma blank y comma blank z are in

    If x comma blank y comma blank z are real and 4 x to the power of 2 end exponent plus 9 y to the power of 2 end exponent plus 16 z to the power of 2 end exponent minus 6 x y minus 12 y z minus 8 z x equals 0, then x comma blank y comma blank z are in

    Maths-General
    parallel
    General
    Maths-

    Let alpha comma blank beta element of R. If alpha comma blank beta to the power of 2 end exponent be the roots of quadratic equation x to the power of 2 end exponent minus p x plus 1 equals 0 and alpha to the power of 2 end exponent comma beta be the roots of quadratic equation x to the power of 2 end exponent minus q x plus 8 equals 0, then the value of ‘r’ if fraction numerator r over denominator 8 end fraction be arithmetic mean of p and q is

    Let alpha comma blank beta element of R. If alpha comma blank beta to the power of 2 end exponent be the roots of quadratic equation x to the power of 2 end exponent minus p x plus 1 equals 0 and alpha to the power of 2 end exponent comma beta be the roots of quadratic equation x to the power of 2 end exponent minus q x plus 8 equals 0, then the value of ‘r’ if fraction numerator r over denominator 8 end fraction be arithmetic mean of p and q is

    Maths-General
    General
    Maths-

    If a comma fraction numerator 1 over denominator b end fraction comma blank c and fraction numerator 1 over denominator p end fraction comma blank q comma fraction numerator 1 over denominator r end fraction form two arithmetic progressions of the same common difference, then a comma blank q comma c are in A.P. if

    If a comma fraction numerator 1 over denominator b end fraction comma blank c and fraction numerator 1 over denominator p end fraction comma blank q comma fraction numerator 1 over denominator r end fraction form two arithmetic progressions of the same common difference, then a comma blank q comma c are in A.P. if

    Maths-General
    General
    Maths-

    If open vertical bar a close vertical bar less than 1 and open vertical bar b close vertical bar less than 1, then the sum of the series 1 plus open parentheses 1 plus a close parentheses b plus open parentheses 1 plus a plus a to the power of 2 end exponent close parentheses b to the power of 2 end exponent plus open parentheses 1 plus a plus a to the power of 2 end exponent plus a to the power of 3 end exponent close parentheses b to the power of 3 end exponent plus horizontal ellipsis is

    If open vertical bar a close vertical bar less than 1 and open vertical bar b close vertical bar less than 1, then the sum of the series 1 plus open parentheses 1 plus a close parentheses b plus open parentheses 1 plus a plus a to the power of 2 end exponent close parentheses b to the power of 2 end exponent plus open parentheses 1 plus a plus a to the power of 2 end exponent plus a to the power of 3 end exponent close parentheses b to the power of 3 end exponent plus horizontal ellipsis is

    Maths-General
    parallel
    General
    Maths-

    The value of not stretchy sum from r equals 0 to n of open parentheses a plus r plus a r close parentheses open parentheses negative a close parentheses to the power of r end exponent is equal to

    The value of not stretchy sum from r equals 0 to n of open parentheses a plus r plus a r close parentheses open parentheses negative a close parentheses to the power of r end exponent is equal to

    Maths-General
    General
    Maths-

    The sum of series 1 plus fraction numerator 4 over denominator 5 end fraction plus fraction numerator 7 over denominator 5 to the power of 2 end exponent end fraction plus fraction numerator 10 over denominator 5 to the power of 3 end exponent end fraction plus horizontal ellipsis infinity is

    The sum of series 1 plus fraction numerator 4 over denominator 5 end fraction plus fraction numerator 7 over denominator 5 to the power of 2 end exponent end fraction plus fraction numerator 10 over denominator 5 to the power of 3 end exponent end fraction plus horizontal ellipsis infinity is

    Maths-General
    General
    Maths-

    If t subscript n end subscript equals fraction numerator 1 over denominator 4 end fraction open parentheses n plus 2 close parentheses left parenthesis n plus 3 right parenthesis for n equals 1 comma blank 2 comma blank 3 comma blank horizontal ellipsis comma blank then fraction numerator 1 over denominator t subscript 1 end subscript end fraction plus fraction numerator 1 over denominator t subscript 2 end subscript end fraction plus fraction numerator 1 over denominator t subscript 3 end subscript end fraction plus horizontal ellipsis plus fraction numerator 1 over denominator t subscript 2003 end subscript end fraction equals

    If t subscript n end subscript equals fraction numerator 1 over denominator 4 end fraction open parentheses n plus 2 close parentheses left parenthesis n plus 3 right parenthesis for n equals 1 comma blank 2 comma blank 3 comma blank horizontal ellipsis comma blank then fraction numerator 1 over denominator t subscript 1 end subscript end fraction plus fraction numerator 1 over denominator t subscript 2 end subscript end fraction plus fraction numerator 1 over denominator t subscript 3 end subscript end fraction plus horizontal ellipsis plus fraction numerator 1 over denominator t subscript 2003 end subscript end fraction equals

    Maths-General
    parallel
    General
    Maths-

    The sum to 50 terms of the series 1 plus 2 open parentheses 1 plus fraction numerator 1 over denominator 50 end fraction close parentheses plus 3 open parentheses 1 plus fraction numerator 1 over denominator 50 end fraction close parentheses to the power of 2 end exponent plus horizontal ellipsis is given by

    The sum to 50 terms of the series 1 plus 2 open parentheses 1 plus fraction numerator 1 over denominator 50 end fraction close parentheses plus 3 open parentheses 1 plus fraction numerator 1 over denominator 50 end fraction close parentheses to the power of 2 end exponent plus horizontal ellipsis is given by

    Maths-General
    General
    Maths-

    The line x plus y equals 1 meets x-axis at A and y-axis at B comma blank P is the mid-point of A B;
    P subscript 1 end subscript is the foot of the perpendicular from P to O A:
    M subscript 1 end subscript is that of P subscript 1 end subscript from O P; P subscript 2 end subscript is that of M subscript 1 end subscript from O A; M subscript 2 end subscript is that of P subscript 2 end subscript from O P; P subscript 3 end subscript is that of M subscript 2 end subscript from O A; and so on.
    If P subscript n end subscript denotes the n to the power of t h end exponent foot of the perpendicular on O A: then O P subscript n end subscript is

    The line x plus y equals 1 meets x-axis at A and y-axis at B comma blank P is the mid-point of A B;
    P subscript 1 end subscript is the foot of the perpendicular from P to O A:
    M subscript 1 end subscript is that of P subscript 1 end subscript from O P; P subscript 2 end subscript is that of M subscript 1 end subscript from O A; M subscript 2 end subscript is that of P subscript 2 end subscript from O P; P subscript 3 end subscript is that of M subscript 2 end subscript from O A; and so on.
    If P subscript n end subscript denotes the n to the power of t h end exponent foot of the perpendicular on O A: then O P subscript n end subscript is
    Maths-General

    General
    Maths-

    Let a element of left parenthesis 0 comma blank 1 right square bracket satisfies the equation a to the power of 2008 end exponent minus 2 a plus 1 equals 0 and S equals 1 plus a plus a to the power of 2 end exponent plus... plus a to the power of 2007 end exponent. Sum of all possible value(s) of S, is

    Let a element of left parenthesis 0 comma blank 1 right square bracket satisfies the equation a to the power of 2008 end exponent minus 2 a plus 1 equals 0 and S equals 1 plus a plus a to the power of 2 end exponent plus... plus a to the power of 2007 end exponent. Sum of all possible value(s) of S, is

    Maths-General
    parallel
    General
    Maths-

    The maximum sum of the series 20 plus 19 fraction numerator 1 over denominator 3 end fraction plus 18 fraction numerator 2 over denominator 3 end fraction plus horizontal ellipsis is

    The maximum sum of the series 20 plus 19 fraction numerator 1 over denominator 3 end fraction plus 18 fraction numerator 2 over denominator 3 end fraction plus horizontal ellipsis is

    Maths-General
    General
    Maths-

    The sum of an infinite G.P. is 57 and the sum of their cubes is 9747, then common ratio of the G.P. is

    The sum of an infinite G.P. is 57 and the sum of their cubes is 9747, then common ratio of the G.P. is

    Maths-General
    General
    Maths-

    If a comma blank b comma and c are in A.P. and b minus a comma blank c minus b and a are in G.P., then a colon b colon c is

    If a comma blank b comma and c are in A.P. and b minus a comma blank c minus b and a are in G.P., then a colon b colon c is

    Maths-General
    parallel

    card img

    With Turito Academy.

    card img

    With Turito Foundation.

    card img

    Get an Expert Advice From Turito.

    Turito Academy

    card img

    With Turito Academy.

    Test Prep

    card img

    With Turito Foundation.