Estimate how many times larger 4 x 1015 is than 19 x 1012.A)20 times larger B)50 times larger C)100 times larger D)200 times larger

(4·10¹⁵)/(19·10¹²) ≈ (4/20)·10³ = 0.2·1000 = 200

The appropriate choice is ...
  D) 200 times larger