Which of the following is the correct value of given number expression...
(2
2 + 4
2 + 6
2 + ... + 20
2)
= (1 × 2)
2 + (2 × 2)
2 + (2 × 3)
2 + ... + (2 × 10)
2= (2
2 × 1
2) + (2
2 × 2
2) + (2
2 × 3
2) + ...
+ (2
2 × 10
2)
= 2
2 × [1
2 + 2
2 + 3
2 + ... + 10
2]
[Formula: (1
2 + 2
2 + 3
2 + ... + n
2)
= (4 × 5 × 77)
= 2 × 77 × 10
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Which of the following is the correct value of given number expression...
Calculation of the given number expression:
First, let's identify the pattern in the given number expression. The numbers in the expression are 22, 42, 62, ..., 202. These numbers can be written as 2^2, 4^2, 6^2, ..., 20^2.
Finding the sum of squares:
To find the sum of squares from 2^2 to 20^2, we can use the formula for the sum of squares of the first n natural numbers: n(n+1)(2n+1)/6.
Let n = 10 (as there are 10 terms from 2^2 to 20^2).
Sum = 10(10+1)(2*10+1)/6
Sum = 10*11*21/6
Sum = 10*77
Sum = 770
Expression in terms of 77:
Now, we have found that the sum of squares from 2^2 to 20^2 is 770.
Given expression can be written as (22 + 42 + 62 + ... + 202) = 77*10 = 770.
Therefore, the correct value of the given number expression is 2 * 77 * 10 = 1540. Hence, option 'C' is the correct answer.
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