If 12+ 22+ 32+ ..... + 20032= (2003) (4007) (334) and (1) (2003) + (2)...
So for 2003 terms the summation is = (2003)(2004)(4007) / 6 = (2003)(4007)(334)
Now,
(1)(2003)+(2)(2002)+(3)(2001)+....(2003)(1) =
= [ 2004(2003)(2003 + 1) / 2 ] - [ (2003)(4007)(334) ]
= [ (1002)(2003)(2004) ] - [ (2003)(4007)(334) ]
= 3 [(334)(2003)(2004) ] - [ (2003)(4007)(334)]
= (2003)(334)( 3*2004 - 4007)
= (2003)(334)(2005)
So the answer is 2005.
View all questions of this test
If 12+ 22+ 32+ ..... + 20032= (2003) (4007) (334) and (1) (2003) + (2)...
Given:
- The sequence follows the pattern of incrementing the number in the units place by 1 each time.
- The last term in the sequence is 20032.
To find:
The value of x in the expression (2003)(334)(x).
Solution:
We can observe that the sequence is obtained by incrementing the number in the units place by 1 each time. Therefore, we can write the sequence as follows:
12, 22, 32, ..., 20032
We can see that the number of terms in the sequence is 2003. Each term can be written as follows:
Term N: N * 10 + 2
So, the last term in the sequence can be written as:
2003 * 10 + 2 = 20032
Now, let's analyze the expression (1)(2003)(2)(2002)(3)(2001)....(2003)(1).
We can see that this expression represents the product of each term in the sequence. So, we can write it as:
1 * 2003 * 2 * 2002 * 3 * 2001 * ... * 2003 * 1
To simplify this expression, we can pair each term as follows:
(1 * 2003) * (2 * 2002) * (3 * 2001) * ... * (2003 * 1)
We can observe that each pair is of the form (N * (2004 - N)), where N ranges from 1 to 2003. So, we can rewrite the expression as:
(1 * (2004 - 1)) * (2 * (2004 - 2)) * (3 * (2004 - 3)) * ... * (2003 * (2004 - 2003))
Simplifying this expression, we get:
2003 * 2002 * 2001 * ... * 3 * 2 * 1
This is the product of the first 2003 natural numbers, which is equal to 2003!. Therefore, the expression can be written as:
2003!
Now, let's go back to the original expression (2003)(334)(x) and substitute the value of the expression we just found:
(2003)(334)(x) = (2003)(2003!)
We need to find the value of x. Dividing both sides of the equation by (2003)(334), we get:
x = 2003!
Using the factorial notation, we can write this as:
x = 2003!
The factorial of a number n is defined as the product of all positive integers less than or equal to n. In this case, the factorial of 2003 is:
x = 2003 * 2002 * 2001 * ... * 3 * 2 * 1
Therefore, the value of x is 2003.
Conclusion:
The value of x in the expression (2003)(334)(x) is 2003. Therefore, the correct answer is option 'A'.
To make sure you are not studying endlessly, EduRev has designed JEE study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in JEE.