Question

$\sqrt{ \frac{1*4*6+2*8*12+3*12*18+...+100*400*600}{1*2*3+2*4*6+3*6*9+...+100*200*300} } =?$

Answer 1

S1 = 4(1·2·3 + 2·4·6 + 3·6·9·+.......+100·200·300) = 4·S2
4S2/S2 = 4 ⇒ √4 = 2