NTA Abhyas JEE Main2020MathematicsSequences and SeriesPractice
If 1 2   +   2 2   +   3 2   +   … . .   +   2003 2 =   2003 4007 334 and 1 2003 +   2 2002 +   3 2001 +   … +   2003 1 =   2003 334 x , then the value of x is equal to
Options
- A2005
- B2004
- C2003
- D2001
Correct answer
A. 2005
Step-by-step solution
Let, S = 1 2003 +   2 2002 +   3 2001 +   … .   +   2003 1 and K = 1 2 +   2 2 +   3 2 +   … .   +   2003 2 Adding both, we get, S   +   K = 2004 1   +   2   +   3   + … .   +   2003 ⇒ 2004 1   +   2   +   3   + … .   +   2003 = 2003 334 x +   2003 4007 334 ⇒   x = 2005 .