(2^2+4^2+6^2+.....+40^2)=?
Answers:
A) 11480	B) 76868	C) 57898	D) 68886	E) 75865
=(1x2)^2+(2x2)^2,+(2x3)^3+......(2x20)^2   =2^2 x (1^2+2^2+3^2+.......+20^2)   formula is =1/6 n(n+1)(2n+1)   =(4x1/6x20x21x41)   =(4x2870)=11480   11480nswer is 11480
<result>A</result>
(2^2+4^2+6^2+.....+40^2)=?