grams of O2 to grams of H2O

Question

If i react 3.7 g of oxygen gas with excess hydrogen, how many grams of water will i produce.

Answer 1

The answer is 4.163 grams and you can report it as 4.2 grams if you wish to answer only 2 significant figures.

The answer is 4.1625 if one wishes to report 5 significant figures. However, since the question is 2 significant figures, 4.2 grams is correct.