Question

SSC Test Questions

If(l^2 +2^2+ 3^2 ..... 10^2) = 385, then the value of (2^2+ 4^2+ 6^2 ..... 20^2) is ?

Answer 1

$(1^2 + 2^2 + 3^2 .....+ 10^2) = 385\\\\(2^2+4^2+6^2+....+20^2)\\\\= (2*1)^2+(2*2)^2+(3*2)^2+...+(9*2)^2+(2*10)^2 \\\\ =2^2*1^2+2^2*2^2+3^2*2^2+....+2^2*9^2+2^2*10^2\\\\=2^2((1^2 + 2^2 + 3^2 .....+ 10^2) \\\\=4*385=1,440$