Question

1*2*3+2*4*6+3*6*9+……+200*400*600

Answer 1

1*2*3+2*4*6+3*6*9+...+200*400*600

--------------------------------- =

1*3*5+2*6*10+3*9+15+...+200*600*1000

1*2*3(1+2^3+3^3+...+200^3)

-------------------------------- =

1*3*5(1+2^3+3^3+...+200^3)

=2/5