(1*2*3+2*4*6+...+200*400*600)/(1*3*5+2*6*10+...200*600*1000)
=1*2*3(1^3+2^3+...+100^3)/[1*3*5(1^3+2^3+...+100^3)]
=1*2*3/(1*3*5)
=2/5