Question

Please answer the question in the picture above

Answer 1

The difference between the masses is
  4.55·10¹³ kg -1.78·10¹² kg
  = 4.55·10¹³ kg - 0.178·10¹³ kg
  = (4.55 -0.178)·10¹³ kg
  = 4.372·10¹³ kg

Rounded to the appropriate precision, the mass of the Antarctic iceberg exceeds that of the Rock of Gibraltar by ...
  4.37·10¹³ kg