(2^2+4^2+6^2+.....+14^2)=?
Choose the correct choice from the following answers:  A) 88  B) 560  C) 99  D) 550  E) 540
=(1x2)^2+(2x2)^2,+(2x3)^3+......(2x7)^2   =2^2 x (1^2+2^2+3^2+.......+7^2)   formula is =1/6 n(n+1)(2n+1)   =(4x1/6x7x8x15)   =(4x140)=560   Answer is 560
<result>B</result>
(2^2+4^2+6^2+.....+14^2)=?