Answer
Verified
405.3k+ views
Hint: We take the value 4 from each number of the series. Then we see that the series in the bracket is a series of squares of natural numbers. Using the formula for the sum of squares of n terms we calculate the sum and multiply it by 4.
* Sum of series \[{1^2} + {2^2} + {3^2} + ......... + {n^2} = \dfrac{{n(n + 1)(2n + 1)}}{6}\].
Complete step-by-step answer:
We are given the series \[4 + 16 + 36 + 64 + ........ + 400\].
We can write the terms of the series as
\[4 = 4 \times 1\]
\[16 = 4 \times 4\]
\[36 = 4 \times 9\]
.
.
.
\[400 = 4 \times 100\]
Since we see that all numbers of the series are factors of 4, we can take 4 common and write the terms of series in the bracket.
\[ \Rightarrow 4 \times \{ 1 + 4 + 9 + 16 + ........ + 100\} \]
Now we can write the terms in the bracket as \[1 = {1^2};4 = {2^2};9 = {3^2},16 = {4^2}.........100 = {10^2}\].
\[ \Rightarrow 4 \times \{ {1^2} + {2^2} + {3^2} + {4^2} + ......... + {10^2}\} \] … (1)
We see that the bracket contains a sum of squares of the first ten numbers.
So, we apply the formula for the sum of squares of first n natural numbers.
\[{1^2} + {2^2} + {3^2} + ......... + {n^2} = \dfrac{{n(n + 1)(2n + 1)}}{6}\]
Since the number of terms is 10. Substitute the value of n=10 in the formula.
\[
\Rightarrow {1^2} + {2^2} + {3^2} + ......... + {10^2} = \dfrac{{10(10 + 1)(2(10) + 1)}}{6} \\
\Rightarrow {1^2} + {2^2} + {3^2} + ......... + {10^2} = \dfrac{{10 \times (11) \times (21)}}{{2 \times 3}} \\
\]
Cancel out the same terms from numerator and denominator.
\[
\Rightarrow {1^2} + {2^2} + {3^2} + ......... + {10^2} = \dfrac{{(2 \times 5) \times (11) \times (3 \times 7)}}{{2 \times 3}} \\
\Rightarrow {1^2} + {2^2} + {3^2} + ......... + {10^2} = (5) \times (11) \times (7) \\
\Rightarrow {1^2} + {2^2} + {3^2} + ......... + {10^2} = 385 \\
\]
Now we substitute the value of sum in equation (1).
\[ \Rightarrow 4 \times \{ {1^2} + {2^2} + {3^2} + {4^2} + ......... + {10^2}\} = 4 \times 385 = 1540\]
So, the sum of series \[4 + 16 + 36 + 64 + ........ + 400\] is \[1540\]
So, the correct answer is “Option B”.
Additional Information:
* Sum of first n natural numbers is given by \[\{ 1 + 2 + 3 + ........ + n\} = \dfrac{{n(n + 1)}}{2}\]
* Sum of cubes of first n natural numbers is given by \[{1^3} + {2^3} + {3^3} + ........ + {n^3} = {\left( {\dfrac{{n(n + 1)}}{2}} \right)^2}\]
Note: Students might make the mistake of solving the value inside the bracket by normal addition which is a very complicated and long process. Students are very likely to make calculation mistakes when adding so many values, so try to avoid calculation by adding these many terms.
* Sum of series \[{1^2} + {2^2} + {3^2} + ......... + {n^2} = \dfrac{{n(n + 1)(2n + 1)}}{6}\].
Complete step-by-step answer:
We are given the series \[4 + 16 + 36 + 64 + ........ + 400\].
We can write the terms of the series as
\[4 = 4 \times 1\]
\[16 = 4 \times 4\]
\[36 = 4 \times 9\]
.
.
.
\[400 = 4 \times 100\]
Since we see that all numbers of the series are factors of 4, we can take 4 common and write the terms of series in the bracket.
\[ \Rightarrow 4 \times \{ 1 + 4 + 9 + 16 + ........ + 100\} \]
Now we can write the terms in the bracket as \[1 = {1^2};4 = {2^2};9 = {3^2},16 = {4^2}.........100 = {10^2}\].
\[ \Rightarrow 4 \times \{ {1^2} + {2^2} + {3^2} + {4^2} + ......... + {10^2}\} \] … (1)
We see that the bracket contains a sum of squares of the first ten numbers.
So, we apply the formula for the sum of squares of first n natural numbers.
\[{1^2} + {2^2} + {3^2} + ......... + {n^2} = \dfrac{{n(n + 1)(2n + 1)}}{6}\]
Since the number of terms is 10. Substitute the value of n=10 in the formula.
\[
\Rightarrow {1^2} + {2^2} + {3^2} + ......... + {10^2} = \dfrac{{10(10 + 1)(2(10) + 1)}}{6} \\
\Rightarrow {1^2} + {2^2} + {3^2} + ......... + {10^2} = \dfrac{{10 \times (11) \times (21)}}{{2 \times 3}} \\
\]
Cancel out the same terms from numerator and denominator.
\[
\Rightarrow {1^2} + {2^2} + {3^2} + ......... + {10^2} = \dfrac{{(2 \times 5) \times (11) \times (3 \times 7)}}{{2 \times 3}} \\
\Rightarrow {1^2} + {2^2} + {3^2} + ......... + {10^2} = (5) \times (11) \times (7) \\
\Rightarrow {1^2} + {2^2} + {3^2} + ......... + {10^2} = 385 \\
\]
Now we substitute the value of sum in equation (1).
\[ \Rightarrow 4 \times \{ {1^2} + {2^2} + {3^2} + {4^2} + ......... + {10^2}\} = 4 \times 385 = 1540\]
So, the sum of series \[4 + 16 + 36 + 64 + ........ + 400\] is \[1540\]
So, the correct answer is “Option B”.
Additional Information:
* Sum of first n natural numbers is given by \[\{ 1 + 2 + 3 + ........ + n\} = \dfrac{{n(n + 1)}}{2}\]
* Sum of cubes of first n natural numbers is given by \[{1^3} + {2^3} + {3^3} + ........ + {n^3} = {\left( {\dfrac{{n(n + 1)}}{2}} \right)^2}\]
Note: Students might make the mistake of solving the value inside the bracket by normal addition which is a very complicated and long process. Students are very likely to make calculation mistakes when adding so many values, so try to avoid calculation by adding these many terms.
Recently Updated Pages
Three beakers labelled as A B and C each containing 25 mL of water were taken A small amount of NaOH anhydrous CuSO4 and NaCl were added to the beakers A B and C respectively It was observed that there was an increase in the temperature of the solutions contained in beakers A and B whereas in case of beaker C the temperature of the solution falls Which one of the following statements isarecorrect i In beakers A and B exothermic process has occurred ii In beakers A and B endothermic process has occurred iii In beaker C exothermic process has occurred iv In beaker C endothermic process has occurred
The branch of science which deals with nature and natural class 10 physics CBSE
The Equation xxx + 2 is Satisfied when x is Equal to Class 10 Maths
Define absolute refractive index of a medium
Find out what do the algal bloom and redtides sign class 10 biology CBSE
Prove that the function fleft x right xn is continuous class 12 maths CBSE
Trending doubts
Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE
Difference Between Plant Cell and Animal Cell
Fill the blanks with the suitable prepositions 1 The class 9 english CBSE
Give 10 examples for herbs , shrubs , climbers , creepers
Draw a diagram showing the external features of fish class 11 biology CBSE
Fill the blanks with proper collective nouns 1 A of class 10 english CBSE
Change the following sentences into negative and interrogative class 10 english CBSE
How do you solve x2 11x + 28 0 using the quadratic class 10 maths CBSE
What is BLO What is the full form of BLO class 8 social science CBSE